A potent surge of Arctic air starts settling in Monday evening as a massive dip in the jet stream pulls in frigid air across the entire eastern half of the country. Temperatures are set to drop as low as 20 degrees below average through Thursday with the highs only reaching the teens and some lows even plunging below zero.

A cold front moved through North Texas overnight, bringing a chilly start to the day with wind chills in the upper 20s. While it will be a sunny Saturday, temperatures will only warm into the mid- to upper-40s.

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.