A flash flood warning for central and southern Cook County and eastern Will County has expired.
The National Weather Service issued the warning Saturday night after a storm with rainfall rates of 3/4 of an inch an hour hit the area. The warning was in effect until 5:30 a.m. Sunday.
Earlier, the weather service issued a flash flood watch for all counties in northeast Illinois, including Cook, Lake, McHenry, Kane, DuPage, Kendall, Grundy and Will. That watch, in effect from 7 p.m. Saturday night through Sunday afternoon, notes that storms may drop 1 to 2 inches of rain overnight.
The concentration of rain was heaviest along the Illinois-Wisconsin line.
The already soaked south and southwest suburbs are especially prone to flash flooding after several rounds of heavy rain in recent weeks.
For more updates, check ChicagoWeatherCenter.com.
The Chicago Tribune contributed to this report.