As of 12:30 p.m., heavy rain had already started to fall in some parts. A flash flood warning was in effect for DuPage and Cook County, the NWS said, with reports of "totally submerged viaducts and underpasses in the city of Chicago."

SAVANNAH, Ga. (WSAV) — As of July of 2025, the United States has experienced the most flash flood warnings since the 1980’s. The National Weather Service (NWS) officially began tracking the data in 1980’s. In the Continental United States, which contains the lower 48 states, has experienced 3,466 warnings.

A round of storms bringing heavy rainfall prompted a flash flood warning in the Chicago area. Another round of storms tonight could exacerbate flooding problems.