Weather
Chicago, IL Weather Alert: 30° Lows Friday After Record 90° Heat Oct 16-17
Chicago, IL – Northern Illinois is heading for a dramatic temperature swing this week as record breaking October heat gives way to the coldest air mass of the fall season, bringing overnight lows near
By Lena Wood · 2026-10-13T01:01:00.614Z
Chicago, IL – Northern Illinois is heading for a dramatic temperature swing this week as record breaking October heat gives way to the coldest air mass of the fall season, bringing overnight lows near freezing in some communities by Friday night, October 16.
According to the National Weather Service in Chicago, temperatures that climbed into the 80s and even lower 90s Monday will fall sharply as a much colder air mass arrives Friday into Saturday.
Forecasters expect afternoon highs Friday and Saturday to remain mostly in the 50s across the Chicago metropolitan area and surrounding portions of northern Illinois.
The coldest temperatures are expected Friday night into Saturday morning , with some western and northwestern communities potentially dropping into the lower 30s.
Areas around Rockford and Dixon could experience overnight lows between 30 and 35 degrees, bringing temperatures close to or below freezing.
Farther southeast, communities including DeKalb, Aurora, Ottawa and parts of the Joliet area are forecast to see lows generally between 35 and 40 degrees.
Chicago and communities closer to Lake Michigan should remain somewhat warmer, with overnight temperatures around 40 to 45 degrees.
The Kankakee area and nearby portions of northeastern Illinois and northwestern Indiana could see temperatures falling into the 35 to 40 degree range.
Residents with sensitive outdoor plants and gardens should monitor updated forecasts as the colder air approaches.
Despite the sharp cooldown, the National Weather Service expects the chilly conditions to be relatively short lived.
Unseasonably warm weather is forecast to return next week , potentially continuing into the following weekend.
Average afternoon highs during that period typically range from the lower 60s early in the week to the upper 50s by the following weekend.
The National Weather Service's October 20 26 outlook favors above normal temperatures across Illinois and much of the eastern United States.
However, forecasters noted that temperatures reaching the 80s become increasingly uncommon this late in October.
For northern Illinois residents, the coming days could bring a remarkable transition from record setting warmth to near freezing mornings before another autumn warmup arrives.