CHICAGO (CBS) – Airlines have resumed operations at O’Hare and Midway international airports Thursday, but there are still more than 1,000 cancellations due to the effects of this week’s blizzard.

WBBM Newsradio 780’s Regine Schlesinger reports the runways are plowed, and air travel is slowly but surely resuming.

LISTEN: Newsradio 780′s Regine Schlesinger reports

The Chicago Department of Aviation reported at 7:30 a.m. that no delays were reported at either airport, but more than 1,000 cancellations were reported at O’Hare, and more than 30 at Midway.

Some of the cancellations are because of bad weather elsewhere, others are due to the logistics of getting the planes and crews where they need to be.

The airlines plan to ramp up their schedules as the day goes on, the department said. The day is expected to be very busy for air travel, as airlines rebook passengers who were stranded during the blizzard.

More than 3,500 flights were canceled at O’Hare on Tuesday and Wednesday, and operations at Midway were shut down altogether Tuesday. While both airports were technically open throughout the blizzard, many airlines canceled their operations to and from Chicago.