More than 1,000 flights in the United States were reportedly canceled on Monday, with more scheduled to be canceled on Tuesday.
The cancellations have been attributed to a severe winter storm.
According to a flight tracking service, FlightAware, a total of 1,019 flights had been canceled as of 6:00 p.m. ET on Monday. Some 4,100 flights were delayed.
Southwest Airlines had the most cancellations, cutting about 12 percent of its schedule, about 483 flights.
As of Tuesday, 797 flights are scheduled to be canceled to or from the United States.
The National Weather Service had said Monday morning that a “prolonged and potentially significant icing event” would affect much of the United States, from the southern Plains to the Tennessee Valley, according to its website.
While the Department of Transportation requires airlines to issue refunds to travelers whose flights are cancelled, affected airlines have issued waivers as winter weather sets in, according to a report by . A waiver allows customers to change their itinerary without fare difference if they stay in the same cabin they originally booked.
Southwest Airlines earlier this month faced backlash from the US government for canceling 16,700 flights over the holidays due to bad weather and outdated technology.
The new cancellations come just weeks after the US aviation industry recovered from a nationwide ground stoppage imposed by the Federal Aviation Administration over a technical issue.