Temperatures rose quickly this morning before storms moved into the area and sent temperatures back into the 70s. The forecast calls for more storms this afternoon and evening.
Temperatures got as high as 88 degrees just before 11 a.m. at O'Hare airport. Storms rolled through the area before noon, bringing relief from the heat, though.
The weather service predicted a high of 91 degrees at O'Hare International Airport, just 4 degrees off the hottest Aug. 25 on record, which occurred in 2003.
The hot and humid conditions may lead to an increased risk of heat-related stress and illness, according to a special weather statement issued Sunday afternoon.
Car interiors can reach lethal temperatures in a matter of minutes.
In addition to the hot and humid conditions, a cold front approaching from the west may help spawn scattered thunderstorms across the area today.