Chicago, Illinois – Drivers across northern Illinois could encounter flooded streets and stalled traffic within hours as intense thunderstorms push rain rates up to 2 inches per hour overnight.
According to the National Weather Service in Chicago, a Flood Watch remains in effect until 6 a.m. Wednesday for a wide stretch of the region, including Cook, DuPage, Kane, Lake, Will, and McHenry counties, as well as Lake County, Indiana. Storms moving through late Tuesday night are expected to produce rapid rainfall on already saturated ground, increasing the likelihood of flash flooding.
In Chicago, low-lying roads, viaducts, and expressway ramps such as I-290 and I-55 are especially vulnerable to quick water buildup. Suburbs including Naperville, Joliet, Elgin, and Schaumburg could see neighborhood street flooding, while Rockford and surrounding areas face rising creeks and drainage overflows. In northwest Indiana, Gary and Hammond may also see ponding on major corridors during the overnight hours.
Officials urge residents to avoid driving through water-covered roads and to charge devices in case of isolated power outages. Those near streams or flood-prone areas should be ready to move to higher ground quickly.
The heaviest rain threat continues through the overnight commute window, with additional alerts possible if storms repeatedly track over the same areas.
