Minnesota weather for the year 1855

Heavy Winter Snows, Dry Growing Season

Weather patterns across Minnesota Territory during 1855 switched back to mostly colder than normal to go with relatively light rains for the growing season Annual mean temperature (42 F) at Fort Snelling tied several previous years for third lowest to date, and for the fourth time in six years, arctic cold spells were felt well into March. Start of a new trend that would mark the next several years, winter snowfall was substantial, and resumption of an old trend, bitter arctic cold, some of the severest ever known, was experienced in December. Annual precipitation at the Post was 24 3/4 inches, more than six inches falling in September.

A Severe, Prolonged Winter – Unaccustomedly heavy snows to go with unseasonable February and March cold marked the balance of the ’54-’55 winter at Fort Snelling. Estimated accumulation of the former, about 50 inches, ranked it one of the four highest since establishment of the Post. January (mean temperature: 11 F) was a month of variety, with record individual day’s warmth, severe arctic cold, and 20 inches’ snowfall on ten days. For the second January in three years, the Post experienced a one-day visitation of spectacularly high temperatures, courtesy of the warm sector of an approaching low pressure center. From a balmy 46 F degrees read at sunrise of the 2nd, the Fort Snelling thermometer exhibited a slow but steady rise during the day to an incredible 56 F by 9PM; Fort Ripley, more than 100 miles to the north, registered 50 F at this latter hour. Following overnight passage of the trailing arctic front, temperatures plummeted all of the next day and night, -11 F registered at Fort Snelling by sunrise of the 4th. Temperatures recovered to thawing levels again by the evening of the 5th, a six-inch snowstorm having swept through during the day, but a week later, bitter arctic cold set upon the area once more, minus 24 F recorded at sunrise on the 13th, the mercury still -22 F at 9AM accompanied by force 4 (25 miles per hour) northwesterlies. Temperatures rebounded to 36 F on the 16th, the 19th near 32 F again, but sharply colder weather ensued, the morning of the 22nd –25 F for the winter’s coldest morning. Afternoon temperatures failed to reach 20 F over the last twelve days. February (mean temperature: 9 F) was well colder than normal but with light snowfall (about 4 inches). Arctic predominance continued over the first week with several mornings around minus 10, no afternoons warmer than the teens, but beginning with the second, a steady pattern of seasonable to mild weather set in, persisting through the third week; afternoon temperatures in the mid-to-high 20’s were the general rule. Warmest (38 F) was recorded on the 20th, but this was abruptly followed by a late, intense arctic outbreak commencing with the 22nd. Minus 23 sunrise readings were recorded on both the 24th and 25th, morning temperatures on the three other days before the month’s close in the -11 F to -16 F range. March (mean temperature: 24 F) brought a great snowstorm followed by several additional late arctic pulses. Spring seemed to be making progress early in the month, afternoon temperatures reaching the mid-30’s to mid-40’s almost daily over the first eleven, a few nights thawing as well. But like ’50, ’52, and ’53, deteriorating weather set in around mid-month. First, a massive wet snowstorm with easterly winds as strong as force 6 (45 miles per hour) dropped about 14 inches at Fort Snelling over the 12th-13th. Cold arctic air drawn down in its wake brought a -2 F reading on the 16th. Following a brief moderation in temperature associated with passage of a much lighter two-inch storm, an even more frigid mass of arctic air then descended over the area. Morning readings of -16 F were registered on each the 20th and 21st, -3 F noted for the 22nd. Changeable day-to-day temperatures made up the rest of the month. The mercury climbed to 48 F on the afternoon of the 23rd, but in the wake of “violent” windstorm on the 26th, yet another cold surge spread over the area. At Snelling, minus 1 F was noted at sunrise of the 27th, accompanied by force 4 (25 mile-per-hour) northwesterlies.

Warm and Dry Spring – After so much unseasonable late cold, April and May brought a marked pattern shift to unseasonably mild and dry, displaying the most sustained anomalous warmth of any April-May combo in the climatic record thus far. The former (mean temperature: 50 F) was the mildest since 1844, just .28 inches’ precipitation recorded from three light thunderstorms. The first two weeks saw gradual warming, afternoon readings generally in the 30’s to 40’s over the first and 50’s over the second. Lake Pepin opened on the 7th, the first steamboat at St. Paul arriving next day. Very warm, almost summery weather prevailed over the last half; more than half the afternoons reached the mid-70’s or warmer, including 86 F on the 17th and 88 F on the 28th. The former broke a highest-so-early-in-the-season mark set just a year ago, the latter setting an absolute highest mark for April. Winds over the last half were predominantly southerly almost every day, the 29th and 30th each with sunrise temperatures in the low 60’s. The Minnesota Daily Pioneer reported on the 27th that “the north[ern] lakes are still closed with ice though the recent warm weather doubtless made an impression”. Warm and dry weather with predominant southerly winds made up the greater part of May (mean temperature: 61 F) also. Most afternoons were in the mid-70’s or warmer, including several in the low 80’s. A 90 F also occurred on the 21st. Lowest was 32 F on the 8th and 35 F on the 9th. Only .29 inches’ precipitation fell over the first 26 days, the “Pioneer” posing the question on the 21st: “When will it rain?” Relief finally came with two thunderstorms on the 27th and 30th that left about an inch.

Mostly Cool and Dry for Summer – Summer ’55 was relatively cool and dry with just a couple of oppressive periods, of short duration. Rainfall remained light, about half of normal, but there were no serious problems with crop yields. June (mean temperature: 65 F), coolest in eight years, had ten of its first thirteen mornings in the 40’s. All but one of the afternoons were confined to the 60’s and 70’s, the exception being a decidedly chilly 54 F on the 1st. Quite anomalous for the first half of June, no rain was recorded over the first 14 days, just .59 inches’ through the 25th. A brief spell of hot and humid weather came over the last week, with 95 F, 94 F, and 95 F recorded on the 26th-28th, respectively; sunrise observations were both 77 F on the 28th and 29th. Four thunderstorms over the last five days dropped 1.79 inches. The 30th, after a frontal passage, registered just 62 F at 3PM, accompanied by force 4 (25 mile per hour) northerlies. July brought a change in the observational format of the meteorological register, readings of temperature reverting back to the pre-1836 scheme of thrice-daily readings at 7AM, 2PM, and 9PM. Winds, still in terms of direction and force, were also observed at these times, the “Clearness of the sky category” replaced by “Fair” or “Cloudy” designations at these hours. Weatherwise, the month was seasonable in temperature overall (mean: 72 F) with continued modest precipitation. Five afternoons reached 90 F or higher, four of these coming on successive days over the 15th-18th. Highest 2PM reading was 96 F on the 18th, the lowest 7AM reading 52 F on the 1st, indicative of an overnight minimum well down into the 40’s. A thunderstorm dropped .50 inch on the 2nd, but just five additional measurable falls were recorded during the month, totaling .82 inch. The Daily Minnesota Pioneer noted on the 19th that the “Hay season is in full blast and the weather is glorious for haymakers”. August (mean temperature: 66 F – coolest in eleven years) brought heavy rains early, with 3.44 inches falling over the first three days. Just .97 inch additional, however, fell before the close. Temperatures were cool to pleasant, only five 2PM readings as high as the 80’s, the warmest a moderate 82 F; seven were confined to the 60’s. The 16th was an autumnal-like 48 F at 7AM, 65 F at 2PM, coupled with northerly winds during the day between force 4 and force 5 (25-35 miles per hour). The Pioneer stated about this time “the air is cold enough to make people shiver and inquire about firewood and stoves”.

Heavy September Rains, Almost Rainless October – Fall, generally seasonable to mild in temperature, provided great contrasting precipitation regimes between September and October. The former (mean temperature: 61 F), like its namesake of a year ago, had the year’s heaviest rains, 6.26 inches falling on 17 days. Over the 7th through 10th, a four-day spell of southeasterlies brought a final warm and humid visitation. Afternoon temperatures climbed to the 80’s, including 88 F on the 10th. But a sharp cool front then passed through, the mercury only 60 F on the afternoon of the 12th, just a few afternoons getting as warm as the 70’s through the close. Geese were reported going south on the 19th, the first frost at Snelling coming on the 26th. Rains were especially intense over the last eight days, 2.20 inches falling over the 22nd-23rd, 1.10 inches over the 24th-25th, and 1.22 inches on the 28th-29th. A fourth storm commenced at 3PM of the 30th, lasting until 10AM on 1 October, totaling .90 inch. The Pioneer on the 2nd remarked about the recent “inclement” weather and the “large quantity of mud in the streets [of St. Paul]”. October (mean temperature: 46 F), on balance, was clear and very dry, with alternating spells of chilly and warm weather. The carryover rainstorm from 30 September provided the month’s only measurable precipitation, the only other precipitation being slight falls of snow on the 21st and 26th. All but three of the first 18 days were predominantly “fair”. The first week had three successive afternoons confined to the 40’s, severe frost occurring on the 5th and white frost on the 6th. Mostly warm and pleasant weather made up the next two weeks, a return visit of frost not coming until the 20th. The afternoon of the 9th reached 78 F, the 18th 79 F accompanied by force 5 (35 miles-per-hour) southwesterlies. Afternoon temperatures were only in the 30’s and 40’s over the 20th to 25th, the mercury dropping to 23 F on the morning of the 23rd for the month’s lowest. But the 27th was 70 F again at mid-afternoon. November (mean temperature: 33 F) featured successive spells of mild and wet, subfreezing, and thawing weather. The opening eleven days had afternoons mostly in the 50’s, as mild as 59 F on the 3rd, the first measurable rain in 35 days, a .90 inch fall, also coming this day. Another inch fell over the 10th-11th. Considerably colder weather ensued, afternoon temperatures from the 14th through 25th generally confined to the 20’s and low 30’s, 7 F recorded on the 21st at 7AM. The 22nd saw the season’s first snow, two inches, laid down. Milder weather then returned, afternoon temperatures reaching the 40’s several times, .29 inches’ snow and rain mixed falling on the 29th.

A Descent to Record Extreme Cold – After a two-year “reprieve”, December (mean temperature: 9 F) brought more early arctic cold, this year’s episode, setting in around Christmas, the most severe ever encountered so early in the season. Week one gave no hint of what was in store, afternoon temperatures reaching the upper 30’s to mid-40’s almost each day, a few thawing continuously for 24 hours. Following 5-6 inches of heavy wet snow on the 8th, though, a gradual but precipitous downward slide in temperature commenced, accompanied by a series of additional snows that accumulated another foot or so over the next two weeks. After a brief storm on the night of the 20th-21st, a vast reservoir of intensely cold arctic air spread rapidly over the area, commencing one of the most bitterly cold weeks ever known in the Fort Snelling experience. On the 23rd the mercury was already down to -24 F by 9PM, and next morning, Christmas Eve, -33 F was read. This broke 1822’s record for most the frigid December temperature ever recorded. Christmas Day was hardly an improvement with minus 26 F, the 26th recording -25 F, and the 28th –26 F. Afternoon temperatures over the 23rd to 29th broke zero just once, the 28th minus 12 F at 2PM. Winds during this long spell, fortunately, were mostly light.