More than 300 flights were canceled Monday evening after a Severe Thunderstorm Watch was issued for most of the Chicago area.
As of about 4:30 p.m., 296 flights were canceled at O'Hare International Airport and average delays of 52 minutes were reported.
At Midway International Airport, 48 flights were canceled and average delays of 15 minutes were reported.
Much of the Chicago area was under the severe storm watch beginning just before 3 p.m. The watch remains in effect until 10 p.m. for nearly all of northern Illinois, including DeKalb, LaSalle, Cook, DuPage, Kane, Kankakee, Kendall, Lake, McHenry and Will counties.
A Severe Thunderstorm Warning was also issued for central DeKalb County and west central Kane County until 5:15 p.m. but was quickly allowed to expire.
A severe thunderstorm was located over Malta, 7 miles southwest of Sycamore, and was moving east at 25 mph, according to the National Weather Service. Quarter-size hail and 60 mph wind gusts were expected.