Nearly 4,000 flights were canceled early Friday as a bitter winter storm engulfed the central and eastern US, throwing Christmas travel into chaos

• Nearly 4,000 flights were canceled by Friday afternoon as a bitter winter storm engulfed parts of the US.
• On Thursday, 2,687 flights within, into, or out of the US were canceled, per FlightAware data.
• Disruptions are set to continue, the National Weather Service warned.

Nearly 4,000 flights were canceled by Friday afternoon as a bitter winter storm engulfed the central and eastern US, throwing Christmas travel into chaos.

By 12 p.m. ET, 3,971 flights scheduled to fly Friday within, into, or out of the US had been canceled, with a further 3,770 delayed, according to data from the flight-tracking service FlightAware.

More than 13,000 US flights were disrupted Thursday, according to FlightAware data; 2,687 flights within, into, or out of the US were canceled, and almost 11,341 were delayed.

The cancellation figures are well above average. In the first nine months of 2022, an average of 497 flights were canceled each day, according to figures from the Bureau of Transportation Statistics.

Flight delays and cancellations will likely impact millions of Christmas travelers. Read Insider's guide on what to do if your airline experiences disruptions.

The National Weather Service said early Friday that the US would experience a "historic winter storm" with more than 240 million people under winter weather warnings or advisories.

The agency has warned of heavy snow, strong winds, and life-threatening cold over the central and eastern US and said wind-chill temperatures of minus 20 to minus 45 degrees F could be seen in some parts of the country by the end of the week. At these temperatures, frostbite to exposed skin can occur in as little as 10 minutes, the agency said.

"This is not like a snow day when you were a kid," President Joe Biden said in a White House briefing Thursday. "This is serious stuff."

Some US airports were hit harder than others during Thursday's chaos. Around a third of the flights to and from Denver International Airport were canceled, and around a quarter to and from Chicago O'Hare International Airport were canceled, FlightAware data shows.

Other airports, including Dallas Fort Worth International Airport, Reagan National Airport, and Seattle-Tacoma International Airport, had a large proportion of their flights delayed, although fewer than 10% were canceled.

In the nine months to September 2022, some 139,683 US flights were canceled, and 1.04 million were delayed, according to data from the Bureau of Transportation Statistics. That's an average of 497 cancellations and 3,708 delays per day.