A thunderstorm warning for Cook and DuPage counties expired at 2:45 a.m. after another 1½ to 2½ inches of rain fell across the metropolitan area, adding to the record July total.
At 3 a.m., Doppler radar showed the storm system had moved east out of the region with the nearest bad-weather system behind it located in northern Missouri.
The rest of the day is forecast to be hot and humid with a 30 percent chance of showers later this morning. A high temperature of 88 is expected.
A flash flood watch for the area was in effect until 7 a.m. In northwest Indiana, a severe thunderstorm watch remained in effect until 9 a.m. for Lake, Laporte and Porter counties. A flash flood warning was issued for Porter and Jasper counties, also until 9 a.m.
The overnight rains left many roads and viaducts flooded, but that situation eased as the morning hours wore on. An exception was West Foster Avenue, which was impassable between North Leclaire and North Lavergne avenues because of a flooded viaduct.
The latest storms added to the number of Commonwealth Edison customers without power. Before the storms, there were still 6,000 homes and businesses without electricity from storms over the previous two days. But the overnight storms, accompanied by gusty winds, added 22,000 to that total, bringing the number to 28,000.
By 5:30 a.m., that had been whittled down to 19,000. Most of those were in the city, which had 11,500 outages. The northern suburbs had 3,600 and the southern suburbs 3,500.
As of 1 a.m., the monthly rainfall total recorded atO'Hare International Airport stood at 10.45 inches. Before this July, the previous July record was 9.56 inches, set in 1889. The overnight rainfall made this July the eighth wettest month ever in Chicago.
The all-time wettest month in Chicago history as August 1987, when 17.1 inches of rain came down.
For updates on the weather, check the Chicago Weather Center.