Chicago, Illinois – Thunderstorms packing torrential rain are set to sweep across Illinois overnight, with the heaviest impacts expected in areas south of I-80 after 2 a.m. Friday. Motorists in Joliet, Kankakee, and surrounding communities could face flooded roads and dangerous driving conditions by early morning.
According to the National Weather Service in Chicago, the strongest storms and most widespread rainfall are likely after 2 a.m., focusing mainly south of I-80. Forecasters warn that locally heavy rainfall will be the primary hazard, increasing the risk of localized flash flooding in low-lying areas, underpasses, and rapid stream or creek rises. All storms will bring lightning and gusty winds, further heightening overnight travel risks.
Residents in Will, Grundy, and Kankakee counties should avoid non-essential travel overnight, especially if roads appear flooded. The National Weather Service urges drivers to turn around rather than attempt to cross water-covered roads. Charging devices, checking local alerts, and having alternate routes ready are recommended as power outages and road closures are possible.
This round of storms follows a wet July for the region, but forecasters note tonight’s setup could deliver some of the heaviest rain totals so far this summer. Warnings remain in effect through Friday morning, with further updates possible if rainfall rates intensify.
