The 1936 North American cold wave ranks among the most intense cold waves in recorded North American meteorological history. The states of the Midwest United States and the Prairie Provinces of Canada were hit the hardest, but only the Southwest and California largely escaped its effects. February 1936 was the coldest month recorded in the states of North Dakota, South Dakota, and Minnesota, and rivals that of 1899 the coldest February on record for the continent as a whole. Only a few parts of the Great Basin, the Bering Sea coast of Alaska and the Labrador Sea coast of Canada were even close to their long-term means.
The 1930s had previously seen some of the mildest winters in recorded North American climatic history – 1930/1931 in the northern Plains and Western Canada, 1931/1932 in the East, 1932/1933 in New England and 1933/1934 in the Western United States. The northern plains had during the previous eleven years experienced six of their ten warmest Februaries between 1895 and 1976 – those of 1925, 1926, 1927, 1930, 1931 and 1935 – with only February 1929 being severe during this period.
Despite a warm March over most areas east of the Rockies, the extended winter from October to March was the fifth-coldest on record over the conterminous United States and the coldest since 1917.
The cold wave was followed by one of the hottest summers on record, the 1936 North American heat wave.
The 1936 cold wave began in the Plains in November 1935, when temperatures were well below normal in all areas west of the Mississippi, and the northwestern states and North Dakota had one of their coldest Novembers on record. December 1935 saw cold weather spread to the eastern half of the United States, when most places were much below average, and Florida saw its coolest December on record, with a mean temperature of 51.9 °F (11.1 °C). Due to chinook winds, however, Montana and British Columbia were significantly above average and the eastern Plains near normal.
The Plains states started to get a taste of what it would be like until March, as North Dakota saw an average temperature of −6.9 °F (−21.6 °C) and the whole of the United States east of the Rocky Mountains was colder than average. The month began with a mild spell in the eastern states, but from mid-month a huge storm moved across the eastern half of the country to cover that region completely by the nineteenth, in the process producing heavy snow and blocking almost all roads in the Appalachian Mountains. Several highway accidents from the snow were blamed for up to 100 deaths.
In the subsequent weeks, as the cold continued, the sea froze partially as far south as Chesapeake Bay, and between 25 and 28 January the East had had its coldest January spell for eighteen years, with Washington, D.C. averaging 14 °F or −10.0 °C Severe winds made wind chills in some locations go down below −85 °F (−65 °C). In the Centralia district and Ohio, the cold completely destroyed the peach crop, whilst defective heaters caused numerous dangerous fires in Minnesota.
Heavy snow and cold created dangerous conditions outside, and many people suffered from frostbite and hypothermia.
February was by far the coldest month in the severe winter. The states of South Dakota, Minnesota, and North Dakota saw their coldest month on record with average temperatures below 0 °F (−17.8 °C) whilst in Canada away from the Atlantic temperatures averaged as much as 36 °F or 20 °C below normal. In Saskatoon, temperatures did not rise above 0 °F or −17.8 °C between January 11 and February 19.
As far south as Richmond, Virginia, rivers were completely ice-bound, and skis had to be used in rescue operations as a succession of snowstorms hit the Pacific Northwest and the whole nation east of the Divide. Thaws accompanied by heavy rain over the South led to flooding, but did not extend beyond the Mason–Dixon line, where food and fuel shortages had created critical situations by the end of the first week of February.
More heavy snow and severe wind chills created very dangerous conditions over the two following weeks. By the middle of the month all schools in the Midwest, Great Plains and Pacific Northwest were closed by deep snowdrifts, and medical aid was affected by a shortage of serum. Many remote South Dakota towns had not had outside contact for several weeks, and in Canada the situation was much worse, with road and rail transport suspended even in cities.
Wind chills in some locations were near −100 °F (−73.3 °C), compelling some people to wear seven layers of clothing before going outdoors. Two states in this brutal February saw their coldest temperatures on record, −58 °F (−50 °C) in McIntosh, South Dakota, and −60 °F (−51.1 °C) in Parshall, North Dakota – whilst an unofficial reading of minus 60 Fahrenheit was also recorded from Jordan, Montana, and an official reading of −63 °F (−52.8 °C) from Sceptre, Saskatchewan. These three states also recorded all-time hot temperatures in July, less than five months later.
Four states saw their coldest winter on record, North Dakota, South Dakota, Minnesota, and Iowa. In one town in Iowa, the average winter temperature was 31 °F (17.2 °C) below average, whilst at Devil’s Lake, North Dakota the average temperature for the five weeks ending February 21 was −21 °F or −29.4 °C. At the peak of the cold wave, stores in the Plains were estimated to generally have only two days’ supply left.
In the final week of February a thaw finally came to the nation. Temperatures rose above freezing for the first time in up to eleven weeks (e.g. at Fargo it reached 32 °F or 0 °C on March 1 for the first time since December 14, 1935). The warming led, however, to avalanches in the Pacific Northwest, where three people were killed on Snoqualmie Pass on February 24.
Above average to near average temperatures were recorded throughout the United States in March, except for the Pacific Northwest, which was not hit as hard by this cold wave as by those of 1949 or 1950. The heavy winter snowfalls and freezing of the ground, along with the wettest March on record in the Northeast led to record floods in most of the region’s rivers, especially on smaller tributary streams.