Weather
Illinois Weather Alert: 90% Storm Chance Tuesday Night Brings Heavy Rain Threat Near I-80
Chicago, Illinois – Chicago area residents could face locally heavy downpours and strong thunderstorms Tuesday into Wednesday as summerlike humidity returns, with rain chances climbing as high as 90%
By Country Herald Consumer Safety Desk · 2026-09-13T20:24:24.855Z
Chicago, Illinois – Chicago area residents could face locally heavy downpours and strong thunderstorms Tuesday into Wednesday as summerlike humidity returns, with rain chances climbing as high as 90% Tuesday night.
According to the National Weather Service in Chicago, Monday stays cooler with highs of 72 to 79 degrees and only a 20% to 30% chance of afternoon showers, mainly across interior northern Illinois. Most locations should remain dry during the daytime.
Conditions change Tuesday as humidity increases and highs reach 78 to 93 degrees. The warmest temperatures are expected south of Interstate 80. Thunderstorm chances increase to 50% to 80% during the day before reaching 40% to 90% Tuesday night.
A few storms Tuesday and Wednesday could become strong to severe. Locally heavy rainfall is another concern, particularly around the I 80 corridor. Drivers should be prepared for reduced visibility, standing water and rapidly changing conditions during heavier storms.
Wednesday remains unsettled with a 50% to 80% daytime storm chance and highs from 71 to 86 degrees. Rain chances continue Wednesday night at 40% to 70%.
Patchy fog is possible across interior northern Illinois tonight, while Chicago and the lakeshore remain milder with overnight temperatures between 45 and 60 degrees regionwide. Residents should monitor alerts as the heavier rain and storm threat increases Tuesday.