Chicago, IL – Illinois will be one of the coldest states in the Midwest during the upcoming Arctic Blast arriving Monday, Dec. 1 through Friday, Dec. 5, with the state entering a prolonged Cold December pattern marked by light snow and widespread subzero wind chill risks.
According to the National Weather Service, early-week disturbances moving across the Great Lakes will bring light snow and flurries to northern and central Illinois, including the Chicago metro area. While accumulations are expected to remain light, visibility may briefly decrease and untreated roads may turn slick during the morning and evening commutes.
Temperatures statewide will plunge into the single digits, with some locations potentially dipping below zero midweek. Forecasters warn that wind chills may fall well below zero, especially north of I-80 and across western and central Illinois. Chicago could experience repeated bouts of wind chills between –5°F and –15°F during the coldest early-morning periods.
The frigid setup aligns with NOAA’s 6–10 Day Temperature Outlook, which places Illinois in one of the strongest below-normal temperature anomalies in the country for Dec. 1–5. Northwest flow behind the Arctic front may also support occasional lake-effect snow near the Illinois–Indiana border.
Though no major winter storm is expected during this period, the combination of dangerous wind chills, patchy snow, and icy travel conditions may impact large portions of the state through the week.
Residents should prepare for prolonged bitter cold and monitor updated NWS advisories as the Arctic air settles in.
