Flights canceled after dense fog covers Chicago Thursday morning

Dense fog in Chicago and surrounding towns Thursday morning caused flight cancellations and delays at O’Hare and Midway international airports.

As of 8:40 p.m., more than 660 flights were canceled at O’Hare because of low visibility, and other flights are experiencing delays averaging 90 minutes, according to the city’s Department of Aviation.

Some flights have also been canceled at Midway and delays are also averaging 90 minutes.

Showers and thunderstorms are likely after 11 p.m. Thursday, and patchy fog was possible before 7 p.m., according to the National Weather Service. Storms are also likely Friday paired with a high of 76 degrees.