A polar vortex is slated to sweep most of the continental United States bringing a hazardous freeze to millions of Americans from the Deep South to the Northeast Saturday going into next week.

Snow and winds are likely to disrupt traffic, trigger flight cancellations, and cause headaches for people traveling to D.C. for Inauguration Day. Baby, it’s cold outside, and it’s about to get even colder for much of the United States.

Most of the U.S. will enjoy milder temperatures on Thursday, but the warmup will be brief as a polar vortex will send temperatures tumbling below freezing for most of the nation starting this weekend.

A Siberian chill is on the horizon, threatening to plunge the U.S. into a deep freeze in parts of the east coast