Weather
Northern Illinois Weather: Sunshine and 70s Through Thursday Oct 22
Chicago, IL – A noticeable October warmup is heading toward northeastern Illinois this week, with temperatures climbing from the upper 50s and lower 60s Sunday to the mid 70s by Wednesday, October 21.
By Miles Carter · 2026-10-18T09:47:18.678Z
Chicago, IL – A noticeable October warmup is heading toward northeastern Illinois this week, with temperatures climbing from the upper 50s and lower 60s Sunday to the mid 70s by Wednesday, October 21. Several days of sunshine are expected, although chilly nights and cooler conditions near Lake Michigan will remain part of the forecast.
According to the National Weather Service in Chicago, Sunday, October 18, will bring bright sunshine and seasonable temperatures before a warming trend pushes afternoon highs above normal throughout the coming week.
Sunday brings sunshine and breezy conditions
Sunday afternoon temperatures are expected to range from 59 to 64 degrees across the Chicago forecast area.
Breezy conditions will develop during the afternoon, but sunshine should dominate the day.
Overnight temperatures will fall between 37 and 41 degrees across the broader region, while Chicago itself is expected to remain milder, with lows generally in the middle to upper 40s.
Temperatures climb toward 70 Monday
Monday, October 19, will bring another sunny day, with highs reaching 66 to 70 degrees.
Tuesday, October 20, continues the warming trend, with temperatures climbing between 68 and 73 degrees.
Overnight lows will gradually become milder, ranging from 41 to 50 degrees Tuesday night.
Wednesday and Thursday could reach 75 degrees
The warmest conditions are expected Wednesday, October 21, and Thursday, October 22, when afternoon highs could reach 70 to 75 degrees.
However, neighborhoods closer to Lake Michigan may remain cooler, with temperatures generally in the middle to upper 60s.
The extended sunny pattern will provide favorable conditions for outdoor activities, commuting and fall recreation throughout the Chicago metropolitan area.
Residents across Cook, DuPage, Will, Kane and surrounding northeastern Illinois counties should prepare for cool mornings followed by increasingly warm afternoons.
No significant precipitation is highlighted in the National Weather Service's five day outlook.