A Tornado Warning briefly issued for Lake and McHenry counties until 2:15 p.m. Monday expired about 11 minutes ahead of schedule, while severe weather continued to threaten much of the Chicago area.
A severe storm capable of producing a tornado was located over McHenry just before 2 p.m., the National Weather Service reported.
A Severe Thunderstorm Warning also was temporarily issued for Will, DuPage and Cook counties until 2:15 p.m. The storms were capable of producing 60 mph winds, the NWS reported.
"For your protection, move to an interior room on the lowest floor of a building," the weather service said.
More than 190 flights at O'Hare International Airport were canceled and more flights were delayed because of flooding at the airport. Inbound and outbound lanes of I-190 were blocked in both directions en route to O'Hare.
Periods of scattered showers and storms, some producing lightning and heavy rain, remain possible for parts of the Chicago area.
Areas north of I-88 are likely to see more storms than those south of the interstate, and while storms will be non-severe, they have the potential to produce very heavy rain, gusty winds and lightning.
Expect highs in the low- to mid-80s for most of the area, upper 70s in far northwest counties and upper 80s in far southern counties. Light and variable winds are expected, except during storms.
Showers and storms are expected to end early, bringing in mostly cloudy, mild and humid conditions overnight with lows in the mid-70s.
Tuesday's return to work and school looks sunnier than cloudy, with only a few isolated showers and storms possible in the afternoon and early evening.
Most areas should remain dry, hot and humid as high temperatures climb into the upper 80s to 90 degrees with a "real-feel" in the mid-to-upper 90s due to high humidity levels.
Heat and humidity continue for Wednesday with showers and storms likely, but a cool-down is on the way for Thursday. Temperatures on this mostly cloudy, breezy day likely will top out in the mid-70s.
Friday looks mostly cloudy with periods of rain, a few possible thunderstorms possible and breezy, mild conditions.