Severe storms, lightning and thunder caused suburban outages and plenty of plane delays overnight.
Between two and seven inches of rain fell since Sunday afternoon, and though flood warnings remained in place Monday for parts of northwest Indiana, the storms mostly have moved on from Chicago.
The intersection of Main and South in Crown Point, Ind., was one of about a dozen spots closed for flooding. Police told NBC Chicago there was so much water a manhole cover was lifted and carried away. One resident said he lost power for three hours.
ComEd reported 300 customers in Oak Park without power. All homes should be back on line by 11 a.m., representatives said.
Frequent lightning may also have caused a house fire in Robbins. Firefighters were called to the home during the storms, though it remains unknown whether the weather sparked the blaze.
Lightning and thunder made a mess of the city's airports, as well. O'Hare Airport reported 325 flights canceled, forcing long lines. Midway also reported delays.
"We stayed in line probably down here five hours, and it's frustrating," said one traveler at O'Hare.
"We were here today for about 13 hours, 14 hours," another traveler told NBCChicago, "and they canceled our flight at 8, and they can't get us out now until 6:05 Tuesday morning."
The good news? Skies should be clear of rain by the afternoon.
Temperatures turn cool, though, from high 50s along the lakefront to 60s inland. Partly cloudy Tuesday afternoon skies will produce another chance for showers and isolated storms. Highs remain in the low 60s Wednesday.