Heavy snowfall socked in the East Coast on January 26, 2026.Mert Alper Dervis/Anadolu/Getty

This story was originally published by Vox and is reproduced here as part of the Climate Desk collaboration.

Already, a bitter burst of cold is gripping much of the country, and in the next few days, it will reach at least 45 states and extend across two-thirds of the country. It is one of the most extreme winter storms in years.

The National Weather Service on Thursday warned that “dangerously cold and very dry Arctic air” will spill into the continental United States and lead to “life-threatening risk of hypothermia and frostbite” as temperatures drop well into negative territory, creating some of the coldest weather on Earth.

For millions of Americans, this is not merely a forecast anymore.

Schools were already announcing closures around the country Thursday morning. Lines were forming at grocery stores. The Texas power grid operator issued a winter warning as it braces for higher electricity demand and disruptions from freezing rain.

“It always ends up colder than the models initially predict, and the models are always playing catchup.”

Wintertime cold is normal. But what is unusual is how this kind of cold tends to arrive: These icy spells sneak up on us, posing a greater challenge to forecasters and leaving little time to prepare compared to slower-moving extremes like heat waves.

“Oftentimes, longer duration signals, such as heatwaves, can be more predictable, whereas short bursts of cold are more difficult to predict,” Matthew Rosencrans, meteorologist at the National Weather Service’s Climate Prediction Center, told Vox in an email.

Cold snaps are especially jarring when they’re interspersed with........

© Mother Jones