Residents all over the NBC 5 viewing area kept their eyes peeled to the sky Monday as quick-moving storms moved through.
National Weather Service issued thunderstorm watches and warning for most of the Chicago area expired by 11:45 p.m.
A Flash Flood Warning were scheduled to expire at 1 a.m. Tuesday for several communites northwest of Chicago.
Flooded residents in Glenview received a double whammy, with hundreds of customers left in the dark from power outages.
Residents in neighborhoods in nearby Des Plaines and Park Ridge were kept busy searching for and clearing drains, hoping they won't see a repeat of last year's flooding. Some of the streets were so flooded, police blocked them off.
Rain rushed down the streets like a river in northwest suburban Elgin where witnesses say the heavy rain and lightning seemed to appear with little warning.
"You never know what's going to happen around here and all of a sudden, bang, you get hit," said Steve Stapay, who drove through the storm.
BP manager Ricky Uppal was about to leave work when the storm hit and water started pouring into his storage area.
"I come back here and it's like flooding all over," Uppal said. "I put plastic down so it won't come back inside.
As of 8:35 p.m., the severe weather was causing delays of 90 minutes or more for inbound and outbound plane at O'Hare International Airport. More than 280 flights wree canceled.
At Miday International Airport, more than 50 delays of 20 minutes or more were reported.
Meanwhile thousands of residents were without power Monday morning in Northwest Indiana after heavy rains and gusting winds lashed the area a day earlier.
Sunday's storms brought lightning and thunder as well as high winds that sent trees into power lines. One wind gust at Gary International Airport at about 7:20 p.m. clocked in at 78 miles per hour.
In Hammond, firefighters had to rescue family members from their SUV after it got stuck in rising floodwaters created by the torrential rain. Crews put the family into a raft and pulled them to higher ground.