2012 Freak March Heat Wave in the Midwest (Blog Update #10)

Never before has such an extended period of temperatures so far above normal been recorded except for the March heat wave of 2012. In some cases, temperatures were 40°F above normal for that time of the year.

Some of the high temperatures in different cities across the the United States were: Bismarck, North Dakota (81° on March 16), International Falls, Minnesota (79° on March 18), Milwaukee, Wisconsin (84° on March 21), Detroit, Michigan (86° on March 22), Cleveland, Ohio (83° on March 21), Bangor, Maine (84° on March 22). Chicago, Illinois, saw daily high records broken or tied for nine consecutive days March 14-22.

The main factor is the heat wave was a warmer than average winter season that had below-average levels of snow cover across the CONUS. This means that there was less thermal energy from the sun required of heat the atmosphere and the air temperature.

The contiguous US saw above normal temperatures in the winter of 2011-12, with numerous northern states surpassing 50°F on January 31st. Courtesy: NOAA Environmental Visualization Laboratory