(CNN) About a thousand flights were canceled Wednesday morning as a winter storm hit the US.
As of 8:40 a.m. Wednesday, a total of 1,004 flights in and out of the United States had been canceled. Southwest Airlines has canceled more than 230 flights so far. According to FlightAware, both Delta Air Lines and SkyWest have canceled about 200 flights.
Minneapolis-St. Paul International Airport and Denver International Airport were the hardest hit, according to early data Flight tracking site FlightAware. Chicago O’Hare International Airport, Detroit Metropolitan Wayne County Airport and Toronto Pearson International Airport also experienced disruptions.
After winter weather warnings were issued for 29 states, including California, Minnesota and Maine, aviation was disrupted as part of a three-day storm with severe ice, bitter cold and sleet warnings.
The Minneapolis, Minnesota area is at risk of at least 15 inches of snow, with the National Weather Service in Minnesota’s Twin Cities warning that the powerful storm will “primarily blow Wednesday through Thursday and bring widespread snow with sleet.”
Correction: An earlier version of this story incorrectly identified Delta Air Lines.
CNN’s Aya Elamroussi also contributed to this article