Maintenance crews restored power to tens of thousands of homes overnight after severe thunderstorms in the Chicago region brought powerful winds and reports of funnel clouds.

Inbound and outbound flights at O’Hare International Airport were delayed 60 to 90 minutes and airlines had to cancel more than 360 flights due to the storms. At Midway, nearly a dozen flights were delayed an average of 2 1/2 hours, and airlines had canceled more than 50 flights, according to the Chicago Department of Aviation.

As a precaution, the White Sox canceled their night game against Toronto. The city canceled all outdoor events at Millennium Park, including the opening night of the Grant Park Music Festival.

The city of Evanston closed facilities and sent workers home early.

It’s a precaution that the city hasn’t had to take since the 2011 blizzard, said city spokesman Eric Palmer.

“We’re taking this seriously,” Palmer said. “This (storm) looks as if it’s going to come into the metropolitan area during rush hour. We want to make sure that we can get our staff home safely.”

Evanston closed all of its facilities as of 3 p.m. and closed all beaches. Officials are also called around to construction sites to make sure that construction materials are tied down and cranes are secured before winds pick up, Palmer said. Most city employees were sent home, but some were held back in case the storms take down trees or cause flooding, Palmer said.

Thursday is expected to be mostly sunny and cooler, with high temperatures in the mid 60s.

Tribune reporters Kim Geiger, Michael Holtz and Alexandra Chachkevitch contributed.

Twitter: @ChicagoBreaking