3.

COLD FRONTS

“The most gloomy and extraordinary weather ever seen…”

MAY DAWNED COLD and dry over the northeastern United States and eastern Canada. A news report from Quebec described “large quantities of snow” in the fields, ice in the St. Lawrence River, and a hard frost on the evening of May 2. In Maine it seemed as if winter had returned, and parts of New York State were still covered with six or more inches of snow. The New York Evening Post blamed the frigid temperatures on “the unusual long spell of cold westerly winds which have prevailed since the spring set in.… Vegetation at this season of the year was never more backward.”

Soon things got worse. On May 12, strong winds swirling down from Canada brought snow and freezing temperatures to New England, killing the buds and leaves on fruit trees. Two days later, Albany, New York, reported that “the ground was covered with snow, and the temperature of the weather during the day more like that of March than May. Rarely has vegetation been more backward at this season of the year than it is now in this city.” Residents of Trenton, New Jersey, awoke to find a “heavy black frost” that had frozen the ground half an inch deep.

On May 14, the cold wave struck crops in Virginia (the National Register reported frost in the vicinity of Richmond), and by one account reached as far south as Tennessee, ruining substantial quantities of cotton. The severe cold exacerbated the effects of a prolonged drought throughout the mid-Atlantic and Southern states, a highly unusual occurrence at that time of year. In Virginia, the Norfolk Beacon reported that farmers were “ploughing up and re-planting the corn. The temperature of the weather with us is very fluctuating—the evenings and mornings generally so cold as to render a fire quite agreeable.” As the cold persisted, ice formed nearly an inch thick on rivers and ponds from Maine to Buffalo. “The season continues extremely unfavorable to Agriculture,” mused a Quebec correspondent. “Masses of snow still lie in the fields, and very little wheat has yet been sown in this district.”

Seasonably warm temperatures returned on May 19, but only briefly. Nine days later, another front swept down upon Quebec from the northwest, bringing more snow and leaving ice a quarter of an inch thick. As the cold advanced through New England, it killed corn in the fields in central Maine. Snow fell in Vermont; the “remarkable cold” froze the ground an inch deep. Cattle could not forage in the pastures, and farmers had to use part of their corn supplies as fodder. “The last spring and the present,” noted the New England Palladium, “are certainly the most backward of any for the last 25 years.” Again the frost reached as far south as Richmond, and as far west as Cincinnati, where blossoms shriveled on the fruit trees.

David Thomas, a farmer in Cayuga County, New York, left his home on May 21 on a journey to explore the lands along the Wabash River in the territory of Indiana, which had recently applied to Congress for admission as a state. As he departed, Thomas wrote in his journal that “the season has been unusually cold, and vegetation proportionally retarded.” Two days later, he noted that “the morning was rainy, cold, and uncomfortable, with wind from the north,” the sort of wind by which “our deepest snows have been borne along.” As he approached the town of Buffalo, he felt a breeze “so damp and chill that instantly we stopt, and put on our great coats.” The following morning (May 25), “was so cold that we shivered in a winter dress, with great coats and gloves.” According to local residents, the spring had been so frigid that the ice along the shore of Lake Erie had disappeared only five days earlier.

Conditions did not improve as Thomas continued westward. He found Chautauqua Lake “wrapt in the drapery of winter,” and a cold rain delayed him for three hours as he neared the border with Pennsylvania on May 28. “This morning was very frosty,” he wrote in his journal on May 29, “and ice covered the water one-fourth of an inch thick.” A brisk breeze from the northeast convinced Thomas to don his great coat again. The next morning he observed “a severe frost”; then “the clouds rolled on heavily to the eastward, and portentously to those who have neither home nor shelter.”

“When the last of May arrived,” wrote a Maine chronicler, “everything had been killed by the cold,” although not much had been planted anyway. “The whole of the month has been so cold and wet,” complained New Hampshire farmer Adino Brackett, “that wheat could not be sown ’til late and then the ground could not be well prepared.” “Everybody complains of the present ‘strange weather; this unnatural weather; this unseasonable weather,’” noted the Chambersburg [Pennsylvania] Democratic Republican. Spring was “at least a month later than usual.” Instead of the usual warm, nourishing showers of April and May, the Eastern United States was experiencing “general aridity, the mountains are covered with snow, the valleys with ice, and the fruits of the earth are stunted and withered. Weather-wise people are at a loss to account for this ‘strange weather.’”

*   *   *

PARIS, too, shivered through a cold and wet springtime, but in May 1816 Louis XVIII appeared to face considerably more pressing problems than the dreary weather. Following Napoléon’s defeat at Waterloo, the Allied sovereigns had reinstalled the corpulent Louis on the throne of France; critics jibed that he had been “brought back in the baggage of the Allies.” But they also had imposed upon Louis the stringent terms of the second Treaty of Paris. France was reduced to its borders of January 1790, which meant the loss of about 5,000 square kilometers and 300,000 citizens; the French people would also have to repay all foreign debts incurred by previous French governments—including, of course, Napoléon’s. Far more damaging were the reparations France would have to pay the Allied victors: 700 million francs over a period of five years, plus the entire cost of feeding and sheltering an Allied occupation force of 150,000 (stationed mostly in eastern France) for at least three years. Adding the annual costs of the indemnity and the occupation troops to the regular budget, Louis’s government in the spring of 1816 was facing short-term obligations of nearly 1,500 million francs, a sum which would require both substantial tax increases and cuts in government spending.

Compounding Louis’s financial woes was the presence of a zealously reactionary Ultra-Royalist majority in the Chamber of Deputies. Led by the Count d’Artois—the king’s brother, who was barely on speaking terms with Louis—the Ultra-Royalists were determined to seek out and punish the “accomplices” of Napoléon, and especially his most vocal supporters during the Hundred Days. Famously “more royalist than the king,” the Ultras knew they could not count on the indolent Louis (whom they privately mocked as “a crowned Jacobin, a King-Voltaire, a dressed-up comedian”) to carry out a thoroughgoing purge of French society. Accordingly, in late October 1815 the Chamber seized the initiative and passed the first of a series of measures that launched the “White Terror,” authorizing the arrest of individuals suspected of plotting against the restored monarchy, and the establishment of special courts to try them.

Doubtless the results disappointed the deputies. Authentic antiroyalist conspiracies were few and far between. “There are continual reports of insurrections and plots,” reported a British military officer in Paris in the spring of 1816, “but it is now well known that the most of them are ‘got up’ by the Ultras to entrap the unwary. The French people seem sunk in apathy and to wish for peace at any rate; nothing but the most extreme provocation will induce them to take up arms.” Meanwhile, the clergy sought to restore the Roman Catholic Church to its privileged pre-Revolutionary position, including the return of real estate that formerly belonged to the Church. Priests whipped up popular sentiment against the alleged enemies of the Church, reportedly forging communications from the Holy Ghost or claiming to have received letters dropped from heaven by Jesus. The result was a series of attacks by Catholic mobs on Protestants, particularly in the south of France; in Nimes, a mob massacred sixteen Protestants during a two-day riot.

Such tactics succeeded mainly in arousing anxiety among the populace, most of whom were willing to tolerate Louis but opposed any attempt to resurrect the Ancien Régime, particularly if it meant returning real estate to the Church. Fearful that the vengeful actions of obdurate reactionaries would alienate the French public to the point of threatening his throne yet again, Louis and his ministers repeatedly opposed the majority in the Chamber, until the nation was treated to the spectacle of Ultra-Royalists defending the prerogatives of the legislature against the king. After beating back an Ultra attempt to abolish divorce, the government at last decided to prorogue the Chamber. On April 29, the king declared the legislative session closed, and his ministers began to plan for new elections in the fall.

A week later, a lawyer named Jean-Paul Didier launched an abortive uprising in Grenoble that collapsed almost before it began. Supported by a force of several hundred peasants and retired soldiers, Didier purportedly sought to overthrow Louis and replace him with Napoléon’s infant son, the King of Rome. Government troops easily quashed the feeble uprising and executed twenty-one alleged conspirators, including a sixteen-year-old boy; Didier, who fled to Savoy, was subsequently captured and executed on June 8. Meanwhile, the police in Paris claimed to have uncovered another plot, this one led by a small group of working men.

To make matters worse, the price of bread was rising due to a shortage of grain from the war and the need to provision the Allied army of occupation. Well aware that he could ill afford to alienate the poor of Paris, who depended upon cheap bread, Louis issued an ordinance permitting foreign vessels to import grain without paying the usual duties. Then he hoped for a plentiful harvest.

“The uneasiness of the court is indescribable,” reported an American correspondent in Paris, “the palace at night may be said to exhibit the aspect of a camp or of a besieged palace. A double line of guards surround it on all sides.” Patrols of gendarmes and the national guard kept watch in every street; coffee houses were cleared at 11 P.M. The London Star reported that ships bound for the United States from French harbors were full of prospective émigrés. “There was a strange feeling of unrest in the country,” concluded one observer, “and there were rumours of the return of Napoléon and of the massacre of nobles and priests.”

*   *   *

WHEN Mary Wollstonecraft Godwin arrived in Paris on May 8, she found her French hosts less than congenial. “The manners of the French are interesting, although less attractive, at least to Englishmen, than before the last invasion of the Allies,” she wrote to a friend; “the discontent and sullenness of their minds perpetually betrays itself.” Doubtless their resentment stemmed from the humiliation of 150,000 foreign troops on French soil, but Mary saw no reason why “they should regard the subjects of a Government which fills their country with hostile garrisons, and sustains a detested dynasty on the throne, with an acrimony and indignation of which that Government alone is the proper object.”

Mary was traveling with her lover, Percy Bysshe Shelley, their infant son, William, and her stepsister, Claire (nee Clara Mary Jane) Clairmont. Nineteen years old in the spring of 1816, Mary Godwin had met Shelley in 1813, and the two fell in love at once. The daughter of William Godwin, a writer notorious for his free thinking and philosophical anarchism—Godwin believed advancing human knowledge and morality would eventually render government obsolete—and noted feminist Mary Wollstonecraft (who died shortly after Mary was born), Mary grew up reading widely in the works of the philosophes, poets William Blake and Samuel Coleridge, and, of course, her parents.

For his part, Shelley was a child of privilege who attended Oxford until the authorities expelled him for his public defense of atheism. In 1811, at the age of nineteen, he had married Harriet Wentworth, then only sixteen herself. Shelley soon tired of monogamy and began to spend much of his time at the home of William Godwin, whose philosophy he admired and whose daughter he subsequently pursued. When he learned that his daughter had fallen in love with a married man, Godwin decided to fall back upon conventional morality and forbade Mary to see Shelley. In late July 1814, the lovers ran off to Europe. By the time they returned in early 1815, Mary was pregnant. The child, born premature, lived only eleven days; Mary later dreamed she could bring her daughter back to life.

Burdened by financial problems and wounded by the critical dismissal of an early poem, “Alastor: Or, the Spirit of Solitude,” published in February 1816, Shelley decided to leave England. Accordingly, he and Mary (accompanied by Claire and three-month-old William) crossed the Channel in early May. Originally Shelley had planned to visit either Italy or Scotland, but Claire—who recently had become the lover of George Gordon, Lord Byron—convinced them to stay in Geneva instead, because that was where Byron would spend the summer. Shelley agreed; at least the cost of living in Geneva was lower than in England.

Their journey by coach from Paris to Geneva took them across the Jura Mountains; Shelley, like Mary, did not regret leaving France and the “discontent and sullenness” of Frenchmen. The weather in the middle of May was far worse than Mary expected. “The spring, as the inhabitants informed us, was unusually late,” she wrote to a friend, “and indeed the cold was excessive; as we ascended the mountains the same clouds which rained on us in the valleys poured forth large flakes of snow thick and fast.” Initially the snow stuck only to the overhanging rocks, but as the coach climbed higher it started to freeze on the road.

Evening fell; the party pressed on, snow pelting against the carriage windows as darkness descended. Then Mary could see Lake Geneva and, far in the distance, the Alps. “Never was scene more awfully desolate,” she noted. “The trees in these regions are incredibly large, and stand in scattered clumps over the white wilderness; the vast expanse of snow was chequered only by these gigantic pines, and the poles that marked our road.”

They settled in a secluded villa known as the Maison Chapuis, a pleasant if humble two-story cottage on the south edge of the lake, facing what Mary termed the “dark frowning” Jura range. On the infrequent evenings that were pleasant and clear, they would sail upon the lake. “Unfortunately,” complained Mary in early June, “an almost perpetual rain confines us principally to the house.… The thunderstorms that visit us are grander and more terrific than I have ever seen before.” One night a brilliant streak of lightning lit up the lake, “the pines on Jura made visible, and all the scene illuminated for an instant, when a pitchy blackness succeeded, and the thunder came in frightful bursts over our heads amid the darkness.”

*   *   *

AS a member of a consortium of New England college professors who regularly made weather observations, Professor Chester Dewey of Williams College kept a thermometer suspended on the north side of his house, well protected from the sun. Three times a day (7 A.M., 2 P.M., and 9 P.M.), Dewey noted and recorded the temperatures, deducing the mean temperature each day from his observations. In the first few days of June, Dewey noticed the temperatures fluctuating wildly, as if on a roller coaster. June 1 and 2 were quite warm; the following two days were much cooler. June 5 brought sweltering heat: At noon Dewey’s thermometer soared to 83 degrees.

It was not an isolated reading. Montreal reported “hot and sultry” weather on June 5. To the east, Boston experienced a high of 86 degrees; at Waltham, the mercury reached 90 degrees; and at Salem, 92 degrees. The Vermont Mirror reported from Middlebury that June 5 was “the warmest day that has here been experienced during the season,” and the Rutland Herald noted “the intense summer’s heat.”

“The mild influence of the sun,” wrote a newspaper editor in eastern Massachusetts, “gave us fond anticipations (tho’ our seeds were but just springing out of the ground,) of a plentiful harvest.” A wave of thunderstorms passed through in the afternoon, cooling the region briefly before unusually high temperatures returned. At ten o’clock that evening, Albany recorded a temperature of 72 degrees, 15 degrees warmer than the normal overnight low temperature. A reporter in Danville, Vermont, could see heat lightning in the distance. “The night was so warm,” noted a resident of Bangor, Maine, “that one blanket was sufficient to keep a person comfortable.” Overnight, a steady rain developed.

The warm, humid air and rain in New England preceded a strong low-pressure system that was making its way across the Great Lakes on June 5. In the Northern Hemisphere, the winds around low-pressure systems spiral counterclockwise; as lows move from west to east, the winds drag warm air from the south ahead (i.e., to the east) of the low-pressure centers. When this warm air meets colder air, such as was present across New England on June 3 and 4, the warm air slowly rises, resulting in steady rain and occasionally in thunderstorms. While these warm fronts are usually benign, lows are often followed by sharp cold fronts, due to the winds pulling cold air from the north. It is cold fronts that most often cause thunderstorms and tornadoes, as the sudden influx of cold air causes the existing warm air to rise quickly.

Highly unseasonable, frigid air lurked behind the cold front of the low that crossed the Great Lakes on June 5. In a weather pattern more typical of winter than summer, a polar high-pressure system was following the low. In summer, Arctic air is usually contained north of Hudson Bay by the subpolar jet stream: strong westerly winds high in the troposphere that effectively form a barrier to weather systems. Occasional southward excursions of this jet stream in winter can produce frigid, but often clear days across the Great Plains and Eastern United States. First in May and then again in June 1816, however, the jet stream dipped far to the south, forming a U-shape and allowing Arctic air to flow from northern Canada as far south as the Carolinas. The collision of this air with the warm, moist air masses that normally prevail in New England and eastern Canada produced powerful storms.

Limited weather observations from the early nineteenth century and the chaotic nature of the atmosphere make it difficult to determine with certainty why the jet stream moved so far south. One explanation is that a broad area of high pressure, a “blocking high,” had developed in late May in the central Atlantic. These systems impede the normal west-to-east flow of the jet stream, causing it to shift north and south to avoid the block. The effect then cascades backwards and forwards along the jet stream in waves, disrupting the jet stream for thousands of miles in each direction and forming the type of U-shaped bends that affected eastern North America in 1816. As with water moving through a clogged pipe, the block slows the movement of weather systems, stagnating the weather and allowing extreme conditions to persist for longer than they might otherwise. A slow, meandering jet stream is consistent with the impact of Tambora’s aerosol cloud on the North Atlantic Oscillation—a weak polar vortex and frequent incursions of Arctic air into the middle latitudes—in the summer of 1816. The aerosol cloud did not necessarily cause the early June storm that struck New England, but the stratospheric veil almost certainly cooled the air behind the storm and set the atmospheric circulation pattern that allowed the air to penetrate so unseasonably far south.

When the low-pressure center and its trailing cold front passed Lake Erie on June 5, several Royal Navy ships stationed there reported strong northwesterly gales as the polar air rushed in. In New Brunswick, central Ontario, the noontime temperature was only 30 degrees. Thunderstorms formed where the air moving behind the cold front began to meet the air brought in by the warm front, bringing heavy rain to western New York and southern Ontario. The low-pressure center continued to move east, while the subpolar jet slipped ever farther south.

Late on the morning of June 6, the cold front and its powerful northwest wind suddenly struck Quebec, turning rain to snow. For more than an hour, snow fell thickly on the city streets. When the sky cleared in the afternoon, residents could see the mountaintops to the north covered with snow, “the most distant apparently to the depth of a foot.” Flocks of birds hitherto found only deep in the forest swarmed into the city in search of warmth, “and were to be met with in every street,” reported the Quebec Gazette, “and even among the shipping. Many of them dropped down dead in the streets, and many were destroyed by thoughtless or cruel persons. The swallows entirely disappeared for several days.” In the countryside, newly shorn sheep perished from the cold.

That night the ground around Quebec froze; the following day the thermometer never rose above freezing, and more snow fell. With the summer solstice less than two weeks away, “the roofs of the houses, the streets and squares of the town, were completely covered with snow,” observed the Quebec Gazette. On the morning of June 8, “the whole of the surrounding country was in the same state, having … the appearance of the middle of December.” More snow fell that day, and more on June 9. An unfortunate traveler about a dozen miles outside of Quebec struggled to plow through snowdrifts that rose up to the axletrees of his carriage. Every night the ground froze, and the wind continued to blow strongly from the northwest, “driving before it an immense mass of lowering clouds, which constantly concealed the sun.” When the sun finally returned on June 10, the land west of the Chaudière River was still covered with snow, in some places about a foot deep.

Montreal received less snow, but on June 7 “the frost was sharp, ice as thick as a dollar [coin], which has injured tender as well as hardy plants.” Since wheat farmers already had planted much of their supply of seeds, the Montreal Herald advised its readers to share their dwindling supplies with their poorer neighbors—and plant as many potatoes as possible, in case the wheat crop failed completely. “Early this morning some snow fell,” the Herald noted on June 8, “and the frost was as severe as on yesterday morning.”

As the low-pressure system tracked across New England on June 6 and 7, the cold front caused temperatures to drop by 30 degrees or more and the winds shifted from mild southwesterlies to gale-force northwesterlies. With Quebec and Montreal already enveloped in snow, a second band of precipitation—first rain, then snow—formed south of the Saint Lawrence River and spread from west to east. In Danville, Vermont, a piercing, cold wind made it seem like November. Snow and occasionally hail began around 10 A.M. on June 6 and continued until evening. “Probably no one living in the country ever witnessed such weather,” claimed the Danville North Star, “especially of so long continuance.” A heavy snow fell in and around Waterbury, about twenty miles north of Montpelier, but much of it melted as it hit the ground, which was still near its normal summer temperature. In the hills outside of Middlebury, however, the snow piled up three inches deep, and Rutland presented “a novel spectacle, to see the ground covered with snow on the 6th of June, and the Green Mountains whitened with the same for two or three successive days.” Some Vermont farmers who had recently shorn their sheep reportedly attempted to tie the fleeces back on the unfortunate animals, but many froze to death anyway. As in Quebec, wild birds flew into barns and houses to flee the cold; “you could pick up numbed hummingbirds, yellow birds, martins, and ‘scarlet sparrows’ in your hand,” recalled one writer, “and many were found dead in the fields.”

At Bennington, a farmer named Benjamin Harwood noted in his diary that “it had rained much during the night and this morning [June 6] the wind blew exceedingly high from NE, raining copiously, chilling and sharp gusts.” It began to snow about 8 A.M., and continued desultorily until early afternoon until about an inch and a half lay on the ground. By the time it was done, “the heads of all the mountains on every side were crowned with snow,” and five of his family’s sheep had been lost in the storm. It was, Harwood concluded, “the most gloomy and extraordinary weather ever seen.”

Snow commenced in Bangor between two and three o’clock in the afternoon. It fell “in beautiful large flakes,” by one account, “some of which as they struck the ground covered spots two inches [in] diameter,” continuing for an hour and a half. The oversized flakes were likely due to the very moist, summertime air that the low-pressure system had pulled up from the Gulf of Mexico. From Jackson, Maine, came a report that June 6 brought “a violent and heavy storm from the west North West, blowing very hard, accompanied with heavy cold rain and snow.” If the precipitation had consisted entirely of rain, it might have totaled six inches or more.

A group of men in Sanbornton, New Hampshire, began the day by assembling timber to build a new schoolhouse. As the cold front passed through, they blew on their hands to keep warm, then stamped their feet and flapped their arms against their sides, and finally cursed the cold as a band of snow forced them back indoors. Eighty miles to the north, bricklayers in the town of Bath quit working on a brick house because their mortar froze. In Waterford, Maine, one elderly gentleman spent the day chopping wood with a heavy coat on, the snow flying in squalls around him.

At Concord, New Hampshire, recently elected Governor William Plumer delivered his inaugural address on the afternoon of June 6 at the local meetinghouse. “The wind blew a gale, with an occasional shower of snowflakes,” recalled one member of the audience. During the ceremonies, “our teeth fairly chattered in our heads, and our feet and hands were benumbed.” As the guests departed town that evening, gusts of wind threatened to overturn their carriages as they crossed Concord Bridge, and when they reached their hotel “we shivered round a rousing fire, complaining of the cold room.”

Throughout New York State, towns at higher elevations reported heavy snow and freezing temperatures on June 6. In Elizabethtown, about 130 miles north of Albany, the rain changed to snow around seven thirty in the morning and continued for three hours, followed by flurries on a strong westerly wind. “The severity of the cold was such as to freeze the ground,” read one report, “and destroy most of the garden vegetables.” Travelers who made it into Albany from the west that day reported a storm “as severe from half an hour to an hour.” At Geneva, “a considerable quantity of snow fell,” and the Catskill Mountains in the southeastern part of the state were covered in snow.

At Williamstown, where it snowed on and off on June 6, Professor Dewey saw that “on the mountain to the west … the ground was white with snow—travelers complained of the severity of the N.W. wind and snowstorm.” Residents of the Berkshires found enough snow to go sledding. Waltham also received snow, strong wind, and rain. In Boston, the mercury dropped forty degrees in less than a day, and snow flurries swirled through the city.

When residents of Waterbury, New York, arose on the morning of June 7, they found ice everywhere. “The situation here, as in other parts of the country, has been uncommonly cold,” noted one correspondent. “But this morning, at 6 o’clock, the thermometer was at 30. Ice three-eighths of an inch thick—and at this moment, 12 o’clock (at noon) ice still in the shade.”

Temperatures hovered around freezing across most of New England on June 7. Towns across Vermont reported ice between half-an-inch and one-inch thick on shallow ponds. “The surface of the ground was stiff with frost,” reported Harwood. “The leaves of the trees blackened … snow remained on Sandgate and Manchester Mountain past noon or as late as that. Wind extremely high night & day and the cold abated but little in the P.M.… Mended fences with greatcoat and mittens on.”

In the Hudson Valley, vegetables were entirely destroyed by frost; in Middlebury, the cold and wind wreaked severe damage on fruit trees. “I well remember the 7th of June,” wrote Chauncey Jerome, a clockmaker in Plymouth, Connecticut, years later. “While on my way to work, about a mile from home, dressed throughout with thick woolen clothes and an overcoat on, my hands got so cold that I was obliged to lay down my tools and put on a pair of mittens which I had in my pocket.” Maine farmers who chose to contribute their labor maintaining county roads in lieu of paying local taxes also found it necessary to don overcoats and mittens.

A severe frost destroyed nearly all the corn planted in Jackson, Maine, about fifty miles north of Augusta. “In the evening,” wrote a correspondent, “the atmosphere [was] so intensely cold, that the small birds, our annual visitors from the southward, sought for shelter in people’s homes and barns, many of them, with the Swallows have been found starved and frozen to death.” The frozen ground also helped kill recently sheared sheep who could find no forage—“the fields as bare of herbage, as usually in the month of November, and the verdure of the forest has the appearance of Fall instead of Summer.”

Crops in Massachusetts also suffered damage. Professor Dewey reported that the ground in Williamstown remained frozen. “Moist earth was frozen half inch thick, and could be raised from round Indian corn [maize], the corn slipping through and standing unhurt. Had not the wind made the vegetables very dry, it is not improbable that they would have been frozen also.”

Cold and frost extended all the way down to New York City. “This morning, the 7th of June, we are told there was ice on this island,” declared a Manhattan newspaper. “Yesterday and to-day our thermometer stood at 50 within doors, the wind is gale and air much colder without; and in the garden we found the vegetables changed in their appearance, and we fear much injured.”

As darkness fell on June 7, another storm brought more snow. This time Vermont sustained a direct hit. Accompanied by bitterly cold winds, snow and sleet began falling Friday night and continued until noon. The town of Cabot received between a foot and eighteen inches of snow, and nearby Montpelier nearly a foot. Drifts outside of Danville piled up to twenty inches. “The awful scene continued,” wrote Benjamin Harwood grimly. “Sweeping blasts from north all the forepart of the day, with light snow squalls.”

On the morning of June 8, temperatures at or just below freezing combined with wind speeds near 30 miles per hour to produce wind chills of 10 degrees. “Still uncomfortably cold, squally, and blustering,” read one Vermont news report. “Winter fires, and winter groups around them.” Farmers donned mittens to work in the fields; others found that the ground was frozen too solid to work at all. One farmer built a fire near his field of corn and enlisted help in keeping it going every night, to keep his crop from freezing. “6th, snowed in considerable quantities,” wrote Adino Brackett, a New Hampshire farmer and teacher, in his diary. “7th also snow. 8th snow. This is beyond anything of the kind I have ever known.”

Snow was reported on the hills outside Amherst, Massachusetts, in the town of Salem, and on the high ground around East Windsor, Connecticut. A traveler who came through western Massachusetts saw “large icicles pending, and the foliage of the forests was blasted by the frost.” A Boston newspaper announced that “snow fell in this town on Saturday [June 8]; and at Wiscasset, and other places, it snowed for several hours in succession. The occurrence is uncommon…”

“I can find no person who has ever before seen snow on the earth in June,” claimed a correspondent in Waterbury, Vermont. “This part of the country I assure you presents a most dreary aspect; great-coats and mittens are almost as generally worn as in January; and fire is indispensible.” The Danville North Star agreed. “The weather was more severe [on June 8] than it generally is during the storms of winter. It was indeed a gloomy and tedious period.”

As the low-pressure system finally began to move out to sea, the subpolar high became entrenched across New England and southern Quebec and Ontario. The high drove Arctic air deep into the valleys, from which it would not be easily extracted. Across Maine, it snowed for three hours on the morning of June 8. The following day temperatures rose slightly, “but still frost and ice—the wind still blowing from N.N.W. and remarkably cold for the season.” Anyone traveling even a short distance needed greatcoats and mittens. Another “most severe frost” struck Maine on the morning of June 10, “that destroyed the blossoms and even leaves of the apple trees in certain directions, accompanied with ice … thicker in proportion, than any night last winter.” As he began to plant his corn that day (considerably later than usual), Joshua Whitman, a farmer in central Maine, noticed numerous birds dead in the fields from the cold. “It has frozen very hard for four nights past,” he wrote. “The ground freezes and is raised by the frost.”

In Middlebury, Vermont, the morning of Sunday, June 9 was “severely cold and … the mountains, not more than two miles east of this village, were completely covered with snow.” News accounts reported icicles nearly a foot long. Moved by the extraordinary weather to an excess of poetic sentiment, the Vermont Mirror claimed that “the very face of nature still appears to be shrouded in a death like gloom, and as she weeps, which well she may, for the barrenness of her fields and for the chilling blasts that whistle through her locks from an unpropicious [sic] clime, her tears freeze fast to her cheeks as they are seen to flow.”

Farther south, visitors to Salem, Massachusetts, found ice in the well at the toll house on the turnpike on the morning of June 9, and frost again in the evening. Fearing the worst for his congregation in South Windsor, Connecticut—and for his own crops—the Reverend Thomas Robbins decided to preach a sermon that morning on the parable of the Barren Fig Tree (Luke 13: 6–9): “A certain man had a fig tree planted in his vineyard; and he came seeking fruit on it, and found none.” Two days later, Robbins concluded that the corn in his fields had been “killed to the ground.”

“Another frost, cold day,” noted Benjamin Harwood in his diary on June 10, “indeed obliged to thrash our hands while hoeing.” Harwood’s corn, which had emerged less than a week earlier, was “badly killed—difficult to see it—gloomy weather.” Professor Dewey, too, recorded a severe frost on June 10: “Indian corn, beans, cucumbers, and the like, cut down.” The morning temperature in Malone, New York, dipped to 24 degrees, the coldest temperature recorded during the entire storm. Even towns along the New England coast reported below-freezing temperatures for eight of the first twelve nights in June, and the snow flurries that swirled into Boston on June 7–8 were the latest recorded seasonal instance of snowfall in the city’s history.

David Thomas was in Pittsburgh, Pennsylvania, when the cold front arrived on June 6. “For three days we had brisk gales from the north-west, of unusual severity for summer,” he wrote in his journal. “The surface of the rivers was rolled into foam, and each night was attended by considerable frost.” As Thomas made his way through the farmlands of Washington County the following week, he encountered extensive orchards of apple and peach trees, “but the fruit has been chiefly destroyed by the late frosts”—the only year it had failed in the past decade. The orchards in southeastern Ohio fared no better; the frosts of June 6–10 left them nearly barren of fruit. “We saw neither peaches nor apples till we approached this [Little Miami] river; and, indeed even here, these fruits are scarce. Dead leaves, in tufts, are hanging on the papaw, and on most other trees—the first growth of this spring having been entirely destroyed. This remark will apply to much of the state where we travelled.”

When warmer weather finally returned late on June 11 (following another frost in the morning), farmers took stock of the cold wave’s cost. “The trees on the sides of the hills, whose young leaves were killed by the frost, presented for miles the appearance of having been burned or scorched,” wrote Chester Dewey. “The same appearance was visible through the country—in parts, at least, of Connecticut—and also, on many parts of Long Island, as I was told by a gentleman of undoubted veracity, who had visited the island.” From Dutchess County in the Hudson Valley came a warning that “the crops of wheat and rye, in this county, which are usually so abundant are almost entirely destroyed.” In Albany, the editor of the Daily Advertiser feared that “great damage has been done by the frosts, which have been so severe as to make ice of considerable thickness.… The prospect to the farmer, as far as we have heard in the country, is, at present, very gloomy.”

Maine farmers reported corn crops “totally destroyed … and even of the sheep that had been shorn, many perished,” even though they had been sheltered in barns. In Portland, the Eastern Argus reported that “a check is given to all vegetation, and we fear the frost has been so powerful as to destroy a great portion of the young fruit that is put forth.” Central Maine suffered significant damage to fruit blossoms, and “in some instances the corn is totally destroyed, the plant being frozen to the seed; in most places it has been cut off to the surface of the ground,” although residents hoped it could still sprout again.

“What is to become of this country, it is impossible to divine—distressing beyond description,” wrote a correspondent from Jackson. “Farms that usually cut from Thirty to Forty tons of Hay, by their present appearance will not cut Five, and to all appearance, this part of the Union is going to suffer for bread and everything else.” In Worcester, Massachusetts, “expectations have in a measure been blasted … and the frost has cut down and destroyed many very valuable fruits of the earth.… A destruction of the crops of grain as also of every species of fruit is fearfully anticipated.” The Brattleboro Reporter agreed that “the most gloomy apprehensions of scarcity are entertained by those who witnessed the phenomena.”

To emphasize the unprecedented nature of the cold spell, news reports repeatedly asserted that the oldest living residents in their community could not remember such violent winter storms in the month of June. The Albany Argus, for instance, declared that “the weather, during the last week, has exhibited an intensity of cold, not recollected to have been experienced here before in the month of June.” In Rutland, Vermont, “the oldest inhabitants in this part of the country do not recollect to have witnessed so cold and unfavorable a season as the present,” and in Middlebury, “never before, we are informed, was such an instance known, by even the oldest inhabitants now living amongst us.”

In the absence of reliable weather statistics, individual human memory—and the collective recollections of a community—were the only means of comparison to previous seasons. But this method clearly had its limitations; as the editor of the Albany Daily Advertiser pointed out, “we are very apt to misrecollect the state of the weather from time to time. Memory is certainly not safely to be relied on relative to this subject, for any great length or time.” Hence the Advertiser urged that regular journals of weather observations should be kept throughout the nation. “A great mass of useful information might be collected concerning our climate, and seasons,” the editorial concluded, “if gentlemen who possess the necessary instruments, would be careful to devote a few minutes in each day to mark the state of the weather, and the temperature of the atmosphere.” Even a modest effort on the part of these individuals, the Advertiser predicted, would provide data which “would be of great and lasting importance.”

A number of Americans (besides Jefferson, of course) already had made sporadic attempts to collect weather statistics in a systematic fashion, although a lack of uniformity in instrumentation and methodology limited the usefulness of their data. In the 1740s, Dr. John Lining—a Scottish-born physician living in Charleston, South Carolina—began tracking changes in the weather with variations in his own physical processes, to try to determine the relationship between climate and public health. “I began these experiments,” Lining wrote, “[to] discover the influence of our different seasons upon the human body by which I might arrive at some certain knowledge of the cause of our epidemic diseases which regularly return at their stated seasons as a good clock strikes twelve when the sun is on the meridian.” Several other physicians in the United States maintained their own records comparing weather and public health data in the late eighteenth and early nineteenth centuries, but there was little coordination of their efforts.

In 1778, Jefferson succeeded in compiling parallel weather observations between Monticello and the College of William and Mary in Williamsburg, Virginia, courtesy of the president of the college, who agreed to take daily readings of the temperature, winds, and barometric pressure. The effort lasted for only six weeks, however. Although Jefferson persistently encouraged the establishment of a national system of meteorological observation throughout the last decades of his life, the best he could achieve was an occasional exchange of information with like-minded souls in cities from Quebec and Philadelphia to Natchez and London. The closest the nation came to achieving a coordinated program of weather measurements before 1816 was the thrice-daily observation system established by the consortium of New England colleges—notably Middlebury, Williams, Yale, and sometimes Harvard—of which Chester Dewey was a member.

Such an accumulation of concrete statistical details was precisely the sort of empirical scientific task that appealed to Americans in the early nineteenth century. As Gordon Wood has pointed out, Americans were forsaking the Enlightenment’s fascination with metaphysical principles and abstract generalities in favor of a harder-edged and utilitarian approach to science. By 1816, science in the United States no longer was the preserve of gentlemen with sufficient leisure to contemplate the moral grandeur of natural laws, or pursue knowledge purely for its own sake. Anyone could gather data (assuming one was armed with the proper measuring instruments), or make sense out of statistics accumulated by others. When introducing his Picture of Philadelphia, a detail-laden snapshot of the city published in 1811, physician James Mease declared that “the chief object ought to be the multiplication of facts, and the reflections arising out of them ought to be left to the reader.” Americans increasingly believed that these collections of scientific data should serve a useful purpose; the study of chemistry, for instance, should produce better cider, cheese, or methods for marinating meat. Perhaps the compilation of meteorological data might result in more efficient agricultural practices. And if scientific investigations helped Americans in their ceaseless pursuit of material wealth, so much the better.

*   *   *

IN the early nineteenth century, most meteorological instruments in the United States and Europe were owned by gentleman scientists, who collected data for their private diaries or to share with their colleagues in learned societies. Many of the rest of the instruments were located on ships: British Royal Navy vessels, for instance, were required to measure the air temperature, ocean temperature, wind speed and direction, and the fraction of the sky covered by cloud four times a day. (In a testament to British military discipline, navy logbooks reveal that ships continued to make regular readings even when taking enemy fire.) Barometers and thermometers were the most common instruments, having been developed over the previous 150 years. While some of the earliest models provided results of questionable accuracy, by 1816 the designs of both instruments had been refined so that they were able to provide precise and reliable measurements of the atmospheric pressure and temperature, respectively.

Anemometers (for measuring wind speed) and hygrometers (for measuring humidity) were far less common and less accurate. There was no standard method for measuring wind speeds until Sir Francis Beaufort’s eponymous scale, developed in 1805, was adopted by the Royal Navy in the 1830s, and wind forces would not be related to anemometer measurements until the 1850s. It is nearly impossible to compare the readings from earlier anemometers, since the designs of the instruments and the scales applied to their measurements varied so widely. Most hygrometers of the early nineteenth century were simply the combination of two thermometers: one kept dry and the other immersed in water. As the water naturally evaporated, it cooled the wet thermometer; the temperature difference between the two thermometers could then be used to determine the humidity. In 1783, the Swiss physicist Horace-Bénédict de Saussure demonstrated the first hygrometer based on the contraction and expansion of human hair due to changes in atmospheric moisture. While his design would later become very popular, in 1816 it had not yet been widely adopted. (Currently, the most accurate hygrometers are polished mirrors that are cooled until water condenses onto them, an adaptation of a technique pioneered by the British chemist John Frederic Daniell in 1820.)

Although barometers and thermometers were in widespread use throughout Europe and the United States throughout the eighteenth and into the nineteenth centuries, many weather diaries remained private; those records that have been published often contain long gaps or end abruptly. The meteorological community was primarily composed of amateurs, albeit enthusiastic ones, rather than professionals. Governments had not yet established official agencies with the responsibility for monitoring or understanding the weather—the Royal Meteorological Society in Britain, for example, was not founded until 1850—and, as during the French Revolution, those that did exist could be disbanded if they became politically unpopular. The information we have today about the climate of the period is the result of the painstaking, meticulous reconstitution by modern climatologists of fragmented data from disparate sources around the globe.

Those nineteenth-century scientists who had access to instruments and kept detailed, regular records would have been aware of the connections between the variations in temperature and pressure and the variations in local weather patterns. Such variations had been noted for nearly two hundred years. Evangelista Torricelli, the Italian physicist and mathematician who invented the mercury barometer in 1643, soon recognized that the atmospheric pressure changed from one day to the next. Four years later, famed French philosopher René Descartes made two identical paper scales for a barometer; one he kept, the other he sent to his friend Marin Mersenne “so that we may know if changes of weather and of location make any difference to [the readings].” In 1648, the French mathematician and philosopher Blaise Pascal carried out a series of experiments on mountain peaks, with the help of his brother-in-law, to demonstrate that air pressure decreases with altitude. His findings astonished most contemporary scientists, who assumed the atmosphere’s composition remained constant throughout its depth.

While the amateur meteorologists of the early nineteenth century understood the links between their own atmospheric measurements and immediate changes in their weather, they were unable to forecast the weather more than an hour or two in advance. Having developed reliable, if elementary instruments and a rudimentary understanding of atmospheric physics, there remained three key challenges that would make accurate weather predictions impossible for another 150 years. The first was the speed at which meteorological data could be transferred and collected at a central location. Forecasting the weather requires accurate information about the current state of the atmosphere. A crude, but often effective prediction technique is to simply use the weather from a nearby location upwind of the location for which one is forecasting. If the wind moves at a greater speed than the information, however, even this technique is useless. Not until the development of a widespread telegraph network in the mid nineteenth century could scientists collect meteorological data quickly enough to make these basic forecasts for a few hours ahead, or warn of the approach of severe weather.

To move beyond the simple, upwind forecasting method, meteorologists must understand the circulations of and interactions between air masses around the globe. As scientists continued to develop meteorological instruments through the seventeenth, eighteenth, and nineteenth centuries, they also developed hypotheses to explain the changes in the readings they obtained. Aided by the instruments aboard ships, many mathematicians and “natural philosophers” turned their attentions to the causes of the direction and strength of the transoceanic winds. These projects carried significant potential benefits to them and their government sponsors, since knowledge of the seasonal variations in the paths of the strongest winds would allow merchant vessels and warships to cross the ocean more quickly than their competitors and enemies.

As the British Empire and the Royal Navy expanded during this period, British scientists engaged in a fierce debate over the origin of the east-to-west trade winds (named for their importance in conveying goods-laden ships to the Americas) that blow steadily across the Atlantic and Pacific in both the Northern and Southern Hemispheres. Some supported Galileo’s earlier hypothesis that the winds were caused by Earth rotating more quickly in the tropics than at the poles; the tropical atmosphere could not “keep up” with the spinning Earth below, they argued. To one standing on the ground, rotating to the east with Earth, the wind would indeed appear to blow from east to west. Others, such as the late-seventeenth-century astronomer Edmund Halley, believed that the winds blew from the east because the sun’s energy flowed from east to west during each day. Halley argued that the sun’s energy heated the air, which rose to form a wind; the sun’s movement caused this wind to appear to blow from the east. Halley’s explanation became canon and was widely accepted in the early nineteenth century.

It would be another twenty years after the eruption of Tambora before scientists acknowledged the true explanation for the trade winds. First advanced—with some inaccuracies—by the British lawyer and amateur meteorologist George Hadley in 1735, the theory stated that the trade winds are caused by air trying to flow from each hemisphere towards the equator. When viewed from the perspective of someone standing on the rotating Earth, however, the winds—which are not rotating—appear to curve to the right in the Northern Hemisphere and to the left in the Southern, giving east-to-west winds in both hemispheres. For his contributions, climatologists still refer to the circuit of winds between the equator and the middle latitudes as the Hadley Cell.

Hadley’s theory was often discussed, but the idea of Earth as a rotating frame of reference was difficult for scientists to grasp. Hadley’s principle did not gain meaningful traction until Gaspard-Gustave Coriolis conclusively demonstrated in 1835 the actions of the various forces acting in a rotating reference frame. (Coriolis, incidentally, thought his work would be most useful for those who built waterwheels, or played billiards.)

Many other fundamental principles of atmospheric science relevant to weather forecasting were developed in the decades following the eruption of Tambora, but remained unknown or as working hypotheses to those attempting to explain the cooling climate and extreme weather after 1815. The Navier-Stokes equations, which describe the three-dimensional flow of viscous fluids, including the atmosphere, were derived in 1845, when George Gabriel Stokes updated Claude-Louis Navier’s 1822 formulation. These equations are crucial to describing the ever-evolving state of the atmosphere; today they form the basis for the computer simulations of Earth’s climate that make it possible to predict the weather days and sometimes weeks in advance. Similarly, the Clausius-Clapeyron relationship, which explains that a greater quantity of water vapor can exist in warmer air, was advanced by its namesakes in the mid-1830s. Without the understanding of the global circulation of the atmosphere that these theories provide, the gentleman scientists of the early nineteenth century lacked the knowledge to understand that volcanic eruptions would affect the world’s weather patterns; certainly they could not have forecast the disruption that the eruption of Tambora would create.

Even with speedily transmitted data by telegraph and comprehension of physical laws that govern the atmosphere, meteorologists failed to produce reliable, useful weather forecasts until after the Second World War due to the third and final hurdle: computational speed. The Navier-Stokes equations and the other key atmospheric formulae require computers in order to generate timely forecasts. The human brain simply is not sufficiently powerful, as the early-twentieth-century British mathematician Lewis Fry Richardson discovered when he tried to apply the equations developed in the nineteenth century to real weather observations. It took Richardson nearly three years—working part-time while serving as an ambulance driver during the First World War—to make a six-hour weather forecast for France, a forecast that turned out to be spectacularly inaccurate.

In the absence of data, theories, and computers, amateur meteorologists of the early nineteenth century fell back upon the centuries-old method of pattern recognition when attempting to forecast the weather and climate. They looked for signs from nature—larger than normal berries on trees, an early appearance of acorns, even the thickness of onion skins—as forewarnings of the coming seasons. (Thin onion skins supposedly meant a mild winter.) Links between these signals and the subsequent climate, whether real or imagined, became established in “weather lore” and provided the basis for many almanacs. Such sayings often thrived due to their adherents’ selective memories, attaching greater importance to the instances in which the lore proved accurate than to those (often more frequent) times when it failed. Some meteorologists of the era also proposed associations between the seasons themselves, such as a cold winter following a warm autumn. In some cases modern science has proven these relationships to be correct, but only because the abnormal conditions in both seasons are caused by the same variation in the atmospheric circulation.