More than 800 Monday flights have been canceled in the US as winter weather bears down on a wide swath of the country.
As of about 3 p.m. ET, about 880 flights within, into or out of the US had been canceled Monday, according to flight tracking site FlightAware, with about 3,000 delays.
Cancellations were already piling up for Tuesday flights, with more than 650 canceled by Monday afternoon.
Most of the cancellations so far are affecting Dallas Love Field and Dallas-Fort Worth International airports in Texas.
On Monday, about 180 flights were also canceled in and out of Denver International Airport in Colorado. For Tuesday, about 100 flights in and out of Austin, Texas, had already been canceled by Monday afternoon.
There's a winter storm warning in effect for a large portion of Texas, including the Dallas-Fort Worth area, until 6 a.m. Central Time on Wednesday.
Dallas-based Southwest Airlines had canceled about 420 flights US flights by 3 p.m. ET on Monday.
The airline, which had an operations meltdown over the holidays, issued a winter weather waiver on Sunday and had extended waivers by midday Monday to a dozen airports in Texas, Oklahoma, Tennessee, Arkansas and Kentucky. The latest waivers apply to travel from January 30 to February 1.
American Airlines issued a waiver on Sunday for Dallas-Fort Worth International Airport (DFW) that applies to travel from January 29 to February 2. American had canceled about 180 US flights by 3 p.m. ET Monday.
Regional carrier SkyWest had canceled about 125 flights by Monday afternoon.
Dallas Love Field tweeted on Monday that its team "stands ready to treat and clear surfaces to allow for safe operations." DFW was also preparing for bad weather.
Both airports urged travelers to check with their airlines for flight status before going to the airport.
The weather will also make for treacherous road conditions. Up to a half an inch of ice or sleet is possible in parts of Texas, the National Weather Service warns. Ice accumulation is expectedacross at least 15 states, the National Weather Service's Weather Prediction Center said.
"If you must travel, slow down and use extreme caution particularly when approaching bridges and overpasses," the Texas warning says.
Motorists are advised to have a flashlight, food and water in their vehicles in case of an emergency. Here's more on what to pack for winter driving.