A monstrous once-in-a-decade winter storm is battering a huge swath of central United States with snow and frigid temperatures, making a mess of highways and canceling thousands of flights as the holiday travel season hits its peak.

Blinding snow squalls and dangerously cold temperatures have gripped the region as an estimated 112.7 million people are set to travel at least 50 miles through Jan. 2, according to AAA. The storm and deep freeze even triggered warnings from the White House.

“This is not like a snow day, you know, when you’re a kid. This is serious stuff,” President Biden said in a briefing on Thursday, calling it “dangerous” and threatening. “If you all have travel plans, leave now. Not a joke.”

More than 2,200 flights have been scrubbed already, with the majority of Thursday’s cancellations in Chicago and Denver, according to the airline tracking service FlightAware. As the storm moves east, travel disruptions are set to strike New York’s LaGuardia Airport, where 158 Friday flights had already been scrapped. Several airlines had waived fees for those looking to rebook.

The arctic front, expected to continue for the rest of the week, is perhaps most remarkable for its sheer size. Snow, blizzard, and flood warnings and advisories stretch from Washington state to Maine and down to the Gulf of Mexico. Frigid temperatures reach as far south as Texas, with Dallas forecast to drop to 11 degrees Fahrenheit on Thursday night.

“It is a really impressive system,” said Ashton Robinson Cook, a forecaster at the U.S. Weather Prediction Center. “It is something that happens only every one or two decades.”

Chicago’s Thursday night forecast is expected to be minus-6 degrees Fahrenheit, with an expected 4 to 6 inches of snowfall driven by wind gusts of up to 50 mph, cutting visibility. Buffalo could get up to 3 feet of snow. New York will mainly see rain starting later Thursday.

Extreme-cold warnings also covered western Canada, while Toronto was under a winter storm watch with forecasters calling for about 5 inches of snow, a flash freeze, and high winds, according to Environment and Climate Change Canada.

While New York and other East Coast cities won’t have to contend with snow and high winds coupled with a new moon – which affects tides – raises the risk of coastal flooding from the Chesapeake Bay to the Gulf of Maine.

Wind advisories and warnings stretched from northern New Jersey to northern Maine, and there’s a risk of moderate coastal flooding in Virginia and throughout New England.

The cold had pushed across the Plains into the Midwest and Texas and was likely to set nearly 80 records – mostly for low daily maximum temperatures – across the country, according to Marc Chenard, a senior branch forecaster at the Weather Prediction Center. Some places could see wind chills that make the cold feel like minus-65 Fahrenheit, which can kill exposed people and livestock.

Farmers are bracing for record colds that could cause machinery to break down, affect winter wheat growth, and freeze livestock at a time of already historic food inflation.

In Texas, where the state’s electric grid was battered by cold early last year, the chill should peak from late Thursday to Saturday and start to moderate early next week, Chenard said. The snow from the storm won’t be that extreme for many places, though high winds will be a problem, he said.