More than 1,000 Monday flights into or out of the United States were canceled due to a severe winter storm in the Midwest, with about half of those operated by Southwest Airlines.
A total of 1,130 flights were canceled by the end of the day, according to flight-tracking service FlightAware.
Low-cost carrier Southwest earlier this month faced U.S. government backlash for canceling 16,700 flights over the holidays as it grappled with bad weather and outdated technology.
The company scrapped about 12% of its Monday schedule, while American Airlines canceled 6%, or 200 flights.
The airports hit hardest were Dallas Love Field, Dallas-Fort Worth International, Austin Bergstrom International and Houston Bush International, all in Texas. Las Vegas’ Harry Reid International and Colorado’s Denver International were also experiencing significant delays.
So far on Tuesday, 1,031 flights have been canceled into or out of the United States, with American Airlines accounting for 10% of the total.
The arrivals board at San Diego International Airport showed numerous evening delays and cancellations Monday, but by Tuesday morning there were only a handful.
Southwest and other major U.S. airlines have issued winter weather waivers. A waiver allows customers to change their itinerary with no fare differences if they remain in the same cabin as originally booked.
Updated at 7:30 a.m., Tuesday, Jan. 31
Reuters contributed to this article.