Chicago, Illinois – Temperatures will dip into the mid-30s across interior northern Illinois overnight, bringing patchy frost before sunrise Monday, May 11, especially west of the Chicago metro.
According to the National Weather Service in Chicago, lows will range from 35 to 45 degrees overnight, with the coldest readings away from Lake Michigan. Communities along and west of Interstate 39 could briefly touch 35 degrees, while Chicago’s lakeshore remains milder.
Frost will develop in sheltered inland areas.
The cooler air arrives under mostly clear skies and light winds, allowing temperatures to fall steadily after midnight. While no travel impacts are expected for the morning commute, gardeners in counties such as DeKalb, LaSalle, and Kane should protect sensitive vegetation.
What residents should do now: Cover tender plants and move potted vegetation indoors before bedtime.
Five-Day Forecast – Northern Illinois
Monday: High 57–67°. Partly cloudy. Lows 38–44° Monday night.
Tuesday: High 72–78°. Windy with a 30–60% chance of showers and thunderstorms, ending in the evening. Low 47–53°.
Wednesday: High 59–67°. Breezy and cooler lakeside. Low 40–46°.
Thursday: High 60–72°. Partly cloudy. Low 48–52°.
Friday: High 72–82°. Increasing clouds. Low 50–60°.
