Storms cause flight cancellations, delays; maybe rain overnight

Thunderstorms off and on today led to delays and more than 500 canceled flights at airports as the rest of the region sweated through what began as a hot and humid day.

Temperatures got as high as 88 degrees just before 11 a.m. at O'Hare International Airport. An initial band of storms rolled through the area before noon, bringing relief from the heat - as much as 20 degrees cooler in some areas, meteorologists said.

A second band of storms arrived in northwest Cook county at about 4:30 p.m. and led to thunderstorms and rain throughout the evening.

When it was all said and done, delays at O'Hare for all flights in and out were an hour or more, while at Midway Airport they averaged 30 minutes or more. Between the two, more than 500 flights were canceled because of the storms.

Rain and some mild storms could move back into the region overnight.

"We are monitoring the potential for redevelopment across that general area very late tonight and early Tuesday morning," said Stephen Rodriguez, a meteorologist with the National Weather Service. "It does look like any severe threats should be limited. Wind gusts of up to 50 mph or small hail, but I'm not expecting severe weather at this time."

Temperatures are expected to be in the low- to mid-80s Tuesday, Rodriguez said.