December 2024 Overview – Midwestern Regional Climate Center

Temperature

The average December temperature for the Midwest was 30.2°F, which was 2.°F above the 1991-2020 normal (Figure 1). Temperatures ranged from near normal to as high as 4°F above normal across the entire region, with anomalies increasing from east to west (Figure 2). Statewide average temperatures ranged from 1.6°F above normal in Ohio to 3.2°F above normal in Iowa, Minnesota, and Missouri (Figure 1). Several quick blasts of Arctic air blanketed the region during the first half of December, resulting in average temperatures of 1-6°F below normal across the Midwest from December 1-15 (Figure 3). The month opened with chilly weather regionwide and single-digit wind chills as far south as Missouri and Kentucky. A strong Alberta clipper ushered in frigid air across much of the Midwest around December 12, causing air temperatures to fall below -20°F in Minnesota and bringing negative wind chills from Iowa eastward to Ohio. Temperatures rebounded for the second half of the month, averaging 6-10°F above normal across the Midwest (Figure 4). Record warm minimum temperatures from December 25-31 were reported at nearly a dozen long-running weather stations across the central Midwest, including in Des Moines (IA), St. Louis (MO), Fort Wayne (IN), Rockford (IL), and Milwaukee (WI).

Precipitation

December precipitation totaled 2.38 inches for the Midwest, which was 0.19 inches above normal, or 109 percent of normal. Precipitation was variable across the region, with a wide swath of above-normal precipitation from southeast Missouri to Michigan and Ohio (Figure 5). Statewide precipitation totals ranged from 0.27 inches below normal in Wisconsin to 1.06 inches above normal in Indiana (Figure 1). A freezing rain event on December 14 brought 0.1-0.7 inches of ice to eastern Iowa, northeast Missouri, western Illinois, southwest Wisconsin, and far southeastern Minnesota. This widespread icing event caused power outages, tree damage, and dangerous road conditions in the area. A notable 2-4 inches of precipitation fell across a wide area of the south-central Midwest from December 15-18, contributing to that area accumulating 150-200 percent of normal precipitation for the month (Figure 6).

Snowfall

Snowfall was below normal across the Lower Midwest, with most of the region accumulating less than 2.5 inches in December (Figure 7). Snowfall totals across Minnesota and Wisconsin ranged from 5-20 inches for the month, which was below normal. Snowfall in Duluth was 12 inches below normal for December. Lake-affected portions of Michigan and extreme northeast Ohio had abundant snowfall in December, with totals ranging from 20-60 inches, which is 100-175 percent of normal (Figure 8).

Drought

The Midwest had modest drought improvements in December, with a 9 percent reduction in areas with drought or abnormal dryness. Improvements were most notable across the Lower Midwest and Michigan’s Upper Peninsula. December concluded with 59 percent of the region dry or in drought, with severe (D2) drought in northern Michigan, north-central Minnesota, and very small portions of western Iowa and southeast Ohio (Figure 9).