Chicago, IL – A powerful Arctic air mass is forecast to plunge across the Great Lakes region between December 12 and December 16, bringing the coldest temperatures of the season, according to the National Weather Service in St. Louis.
Forecast confidence is high, with the NWS indicating a 60–80% chance of below-normal temperatures throughout Michigan, Ohio, Wisconsin, Illinois, and northern Indiana. Daytime highs may stay in the 20s, while overnight lows drop into the teens and single digits. Combined with brisk northwest winds, wind chills could fall below zero at times, particularly near Lake Superior and Lake Michigan.
Meteorologists warn the cold pattern could also trigger lake-effect snow, especially downwind of the Great Lakes. Residents are advised to dress in layers, avoid extended time outdoors, and check on vulnerable neighbors and pets during the coldest nights.
The Arctic outbreak is expected to moderate gradually late next week, though another surge of cold air may follow later in December.
