The Coldest March Outbreak in Years Breaks Records in Rockies, Plains and Midwest

An all-time March record low for the entire state of Montana may have been set at Elk Park March 4, when the temperature fell to minus 46 degrees. Three other Montana cities, Eureka (minus 23 degrees), Miles City (minus 31 degrees) and Livingston (minus 27 degrees) set new record lows for the month of March.

Another location in northeast Montana plunged to minus 44 degrees on March 3, one of the coldest March temperatures on record in northeast Montana.

One local resident on northwest Montana's Flathead Lake noted it was the first time he had seen Wood's Bay freeze up in 30 years.

Pullman, Washington, set an all-time March record low two straight mornings, plunging to minus 5 degrees March 3, then minus 9 degrees the following morning. Wenatchee, Washington, also set a new record March low of 4 degrees March 4.

North Platte, Nebraska, also set an all-time March record low of minus 25 degrees on March 4, tying the third coldest March low in state history, coldest since March 1, 1980, according to the National Weather Service.

Chicago fell below zero on March 4, something that has happened only eight other March days on record at O'Hare Airport, last occurring March 3, 2014. It was also the coldest March morning there since March 4, 2002.

Daily record lows for March 4 were set in Duluth, Minnesota (minus 19 degrees), and Indianapolis (2 degrees - tie).

Daily record lows for March 3 were also set Sunday morning in Sioux Falls, South Dakota (minus 17 degrees), Billings, Montana (minus 19 degrees), Rochester, Minnesota (minus 17 degrees - tie), and Minneapolis/St. Paul (minus 13 degrees - tie).

Denver dropped to minus 6 degrees Sunday morning, which is the coldest March low temperature there since March 2, 1960, according to the National Weather Service.

While not an all-time March record, Cheyenne, Wyoming, plunged to their coldest March temperature since 1948, tumbling to minus 16 degrees on March 4.

Rochester, Minnesota, spent 36 straight hours below zero from just before midnight on March 1 through just before midday on March 3, their second-longest March subzero streak on record.

Daytime high temperatures were notably cold, as well.

While not all-time March records, high temperatures were the coldest for any March day in 69 years in South Bend, Indiana, and 57 years in Ft. Wayne, Indiana.

Pine Bluff, Arkansas, had only its 10th March day on record in which the temperature did not rise above freezing.

Wind chills in the minus 40s were seen in parts of the Dakotas and Minnesota, and minus 50s wind chills were recorded in parts of Montana and North Dakota.

(MORE: The Danger of Wind Chill)

If there was one small ray of light to this, it wasn't be nearly as cold in the upper Mississippi Valley and western Great Lakes as a late-January cold outbreak, which included some all-time record lows. It is March, not January, and those increased hours of daylight and more direct sunlight do make a little difference.

Why Was it So Cold?

This latest cold outbreak was due to a blocked jet-stream pattern in the Arctic.

Namely, a nose of high pressure aloft from the Gulf of Alaska to the Canadian Arctic forced bitterly cold air south into the U.S.

This arctic block was also responsible for abnormally mild weather in parts of Alaska, including record warmth at America's northernmost city, Utqiagvik, formerly known as Barrow.

Followed a Frigid February

February's monthly mean temperature – basically, the average of each day's high and low – was below zero in parts of Montana and North Dakota.

According to the Southeast Regional Climate Center, it was the coldest February on record in Rapid City, South Dakota, and the second-coldest such period in Great Falls, Montana.

Neither Bismarck, North Dakota, nor Glasgow, Montana, have had a single day warmer than average since Groundhog Day.

(MORE: February a Record-Breaker From Coast to Coast)