Minnesota weather for the year 1850

Heavy Winter Snows, Spring and Summer Floods (graphic)

The first full year of Minnesota as an organized Territory was a memorable one, weatherwise, with the unusual occurrence of spring and summer floods in the same year. Following the snowiest winter since perhaps 1825-6 or 1835-6, April brought damaging floods, prompting mention of the Spring of 1826 in the year-old St. Paul newspaper. Heavy rains in June and July created even higher river stages, resurrecting mention of the other great (summer) flood of the historical experience, 1822. Annual mean temperature at Fort Snelling (44 F) was the highest in four years, total yearly precipitation 25 1/2 inches.

More Heavy Snows – January (mean temperature: 13 F), relatively uniform in temperature, brought additional heavy snows, creating a depth not seen locally for many years. Continuing the old year’s closing cold snap, New Year’s Day morning at Fort Snelling brought a bitter -16 F, the 3rd and 4th -15 F and -11 F, respectively. Readings this low, however, would not be experienced again through the close, the coldest a comparatively moderate -7 F. Low to mid-30’s’ temperatures were reached on a few scattered afternoons, but no thawing spells of any appreciable duration occurred. Two snowstorms separated by only a day struck after mid-month, four inches left on the 19th, “a very severe snowstorm” accompanied by “high winds” accumulating another foot over the 20th-22th. Added to December’s falls, snow depths at Snelling were probably as great as any seen at this stage of the season for at least a decade. February (mean temperature: 17 F) had a cold first half, a mild second, and diminished snowfall. The winter’s coldest reading came on the 3rd with –24 F read at sunrise, -22 F registered at the same hour on the 4th. Another less intense cold spell around mid-month brought several mornings around -5 F, but most of the remaining days were thawing for the afternoons, the 26th 43 F at 3PM for the month’s highest temperature. Just .08 inch of melted snow having been recorded through the 27th, the last day of the month brought 0.75 inch of snow and rain mixed.

Backward Spring, Floods – March (mean temperature: 23 F) brought two additional storms, significantly increasing the potential for spring flooding. Temperature advance all month was slow and erratic, only a handful of afternoons as warm as the 40’s, near subzero cold felt as late as the last week. On the night of the 12th and 13th, a “heavy fall” of snow and rain mixed dropped 1.00 inch water content, and just four days later a 10-inch snowstorm buried the Post. Cold weather didn’t follow immediately, the next several days thawing in the afternoons, but over the 23rd to 26th, an unseasonably late arctic air mass overspread the area, morning readings at Snelling around 5 F on each day, afternoon readings on three of the four days no higher than the teens. The 23rd was especially raw, the mercury just 17 F at 3PM with force 5 (35 miles per hour) northwesterlies. Total (estimated) snowfall for the season was now at least 55 inches, fully up to the amounts if not exceeding those of ’35-’36 and ’25-’26. April, exceptionally cool, cloudy, and damp, had the lowest mean temperature (38 F) since 1826. Temperatures were unseasonably chilly virtually throughout the month, afternoon readings not passing the 50 F mark until the very last week. Heavy rains over the opening days virtually clinched the likelihood of flooding, nearly 2 1/4 inches of rain falling at Snelling over the first four. In the Twin Cities vicinity on the 8th, the Mississippi river began to rise with the ice starting to run. The editor of the Minnesota Pioneer reported two days later: “last evening in St. Paul [the 9th] we could hear the noise of the masses of ice tumbling over the Falls of St. Anthony, 8 miles distant”. Expectations of high water were now general: “The Indians say the snows in the North are very deep and that we may expect the water to be higher that it has before been for 25 years”, in obvious reference to 1826. Both the Mississippi and St. Peters continuing to rise past mid-month, submerging warehouses and sweeping “great quantities of firewood” past the St. Paul levees. At St. Anthony, also about this time: “…ice crowding into the boom above the mills has driven an immense herd of logs upon the [containment] dam, where they stand and lie tumbled up in admirable confusion”. To go with the high waters, a “steady blast sweeping down from the Northwest” brought exceedingly blustery and cold weather over the 12th-14th, gale-force winds and afternoon temperatures in the upper-20’s and 30’s experienced at Snelling. Summing up events on the 17th, the Pioneer declared: “such a flood has not been known [here] for many years.” Spring-like weather finally made an appearance on the 24th and 25th, the mercury, behind strong southerly winds, soaring to 73 F and 74 F, respectively, on the two days. The month closed out cold and damp again, the 30th only 41 F at mid-afternoon accompanied by strong northwesterlies. The season’s first boat, the “Highland Mary” had arrived at St. Paul on the 19th, Lake Pepin having become open on the 10th. Early May showed scarcely any thermal improvement with eight out of the first ten afternoons confined to the 40’s, most mornings near freezing. Cloudy skies and occasionally strong west to northwesterly winds also prevailed. On the 12th, though, sunny skies and strong south-westerlies brought 77 F at mid-afternoon, the rest of the month’s afternoons mostly in the 60’s and 70’s. The 15th and 24th were each 86 F. Monthly mean temperature finished at 56 F, rainfall for the month .57 inch.

Warm, Muggy, Wet Summer, More Floods – Summer was notably warm and wet with frequent heavy rains and many sultry uncomfortable nights, a second even more pronounced episode of flooding coming in July. June (mean temperature: 71 F), warmest in eleven years, received 4.62 inches of rain on twelve days. Most afternoons were in the upper 70’s to mid-80’s, nights, especially after the first week, generally no cooler than the mid 60’s. The 14th-18th was especially wet, a series of almost daily thundershowers dropping 3.09 inches over the interval. Fort Snelling diary notes had the Mississippi rising on the 18th, both it and the St. Peter’s “both very high” on the 27th. Rains continued frequent and heavy throughout July, resulting flood levels even more pronounced than April. At Snelling, 6.17 inches fell during the month, 3.30 inches coming on the 1st alone. Rivers were at or near flood stage from all areas of the Territory that were heard from. On the 18th, the Minnesota Pioneer reported the Mississippi to be “higher than it was in the Spring freshet, higher than it has been for 28 years”, another obvious reference to the other great flood of the historical experience — June 1822. Similar to Spring, there were more warehouse inundations, and upstream at St. Anthony, the sawmills were closed for a time, a containment dam sustaining more damage. The heavy rains extended far to the Northwest as well, another account from the 18th relating: “we learn that the freshet is so great in the Red River Valley of the North that the inhabitants have been compelled to abandon the entire valley of the river and flee for safety to the highlands”. A visitor just arrived from Lac Qui Parle also reported that “within a distance of 150 miles up the St. Peter, on both sides, the whole country is swarming with buffalo, which have been driven down by the freshets of the northern rivers”. All was not misery and gloom, though. Taking [the usual] advantage of the high river stages, a number of special steamboat excursions were made during July, “the commencement of [regular] navigation of the Minnesota River by steamboats” [Williams, 1881]. The most adventurous one was undertaken by the “Yankee”, which reached “300 miles up the St. Peter’s River” or about “80 miles up from the Cottonwood River” on the 23rd. Plans were to go as far as Lac Qui Parle, but owing to “excessive heat, want of dry fuel, ice, mosquitoes, chance of sickness amongst women and children, and risk of accident stranding in the wilderness”, the party turned back. Similar runs were made on the Upper Mississippi, steamboat navigation “opened to Sauk Rapids, demonstration of the practicability of running small steamboats as far as Pokegama”. Conditions during July were warm and sultry (mean temperature: 76 F), more than half the mornings at Snelling with sunrise readings warmer than at least 70 F, assuming proper ventilation in the Fort enclosure. Five afternoons reached the 90’s, including 97 F on the 16th and 98 F on the 24th. August, also warm and humid, tied 1846 for 2nd warmest (mean temperature: 74 F) in Post history. Some 2.97 inches of rain fell, the bulk of this over the second half. Most afternoons through the 16th continued to reach the mid-to-upper 80’s, all but two of the sunrise temperatures at 70 F or warmer. Just two rains totaling .60 inch fell. Thunderstorms on the night of the 17th, however, started a cooling trend, the remaining days with afternoon temperatures generally in the low to mid-70’s, nights mostly in the low 60’s. The 31st, however, was the coolest day since early May, daily temperature range just 50 F to 62 F with northerly winds as high as force 5 (35 miles per hour).

Mild, Dry Fall – After all the precipitation and associated flooding of the year thus far, weather patterns switched to mostly fine and dry for the remaining months. Temperatures, with the exception of December, showed a relatively gradual decline. September (mean temperature: 61 F) was mild with only a few mornings dropping as low as the 40’s. Afternoon temperatures were very uniform on a day-to-day basis, all but three of them in the 60’s and 70’s. The only exceptions were 80 F on the relatively late date of the 20th, and coolish 59 F readings on the 26th and 28th each. Slight frost was reported on the 17th and 19th, and again on the 28th. Total rainfall was 1.72 inches on 8 days. October (mean temperature: 49 F) was sunny, dry, and mild with many Indian-Summer-like days. Twenty-three afternoons had clearness-of-sky statistics of from 8 to 10, indicating cloud-free or nearly so skies. Just four rains were recorded, totaling .32 inch. Nippy weather occurred early, the mercury dropping to 32 F at sunrise of the 6th, with Surgeon McLaren noting: “first ice appeared visible on water”. Most mornings from this point on were in the 30’s and 40’s, afternoons principally in the upper 50’s to 60’s. The prairies were on fire on both the night of the 27th and during the day of the 28th. November (mean temperature: 34 F) was also relatively mild and dry. “Heavy rain” on the 3rd and 4th dropped 1.30 inches, but the next measurable precipitation would not come for another 21 days, a 1/4 inch rain over the 25th-26th. Atmospheric conditions on the 9th were “smokey and dark … caused by the prairies being on fire”, the 22nd reporting the “prairies on fire last night & today”. Afternoon temperatures, in the upper 40’s to mid-50’s over the first week, were confined in monotonous fashion to the 30’s for most of the remaining days, a few failing to reach freezing. Coldest day was the 30th, with 15 F and 22 F, respectively, at sunrise and 3PM.

Steady December Cold – December (mean temperature: 12 F) repeated the script of 1848 with not a single observed temperature above freezing. Arctic weather set almost from the start, four mornings in a row beginning with the 4th in the -10 F to -14 range, the Mississippi freezing over on that first day. The month’s remaining days displayed a steady, more moderate cold, most mornings in single figures or teens, afternoons in the teens or low 20’s. A number of “slight” snows, mostly unmeasurable, left about 1 inch total, using the 10 to 1 rule in converting amounts reported in the gauge to snow depth approximations.