A dangerous cold snap is sweeping across the United States, with life-threatening wind chills ranging from -30 to -55 degrees expected in the Rockies, northern Plains, and Upper Midwest. A lobe of the polar vortex has plunged temperatures to bone-chilling levels, making this one of the coldest stretches of winter in recent years.

While this winter has been relatively mild until now, the weather has taken a drastic turn, affecting nearly every region in the Lower 48 states. A rare winter storm is also hitting the Gulf Coast and the South, with Winter Storm Warnings in effect from Texas to Florida. On Sunday, heavy snow battered the heavily traveled I-95 corridor, from Washington, D.C. to Boston, impacting millions of people.

According to the National Weather Service, temperatures have dropped sharply across the Rockies, Plains, and Mississippi Valley, and the East Coast is now experiencing the freeze, which is expected to last into midweek. In Washington, D.C., the presidential inauguration of Donald Trump was moved indoors to the United States Capitol Rotunda due to the extreme cold.

These frigid temperatures are some of the coldest of the season and, in many cases, the coldest in years. The combination of subzero temperatures and harsh wind chills presents a serious risk to health and safety. In International Falls, Minnesota, wind chills could dip to -45 degrees on Tuesday morning, while Chicago will feel like -21 degrees.

Even cities not typically associated with extreme cold, like Montgomery, Alabama, are bracing for wind chills in the teens. In total, over 30 states are under cold weather alerts, including Extreme Cold Warnings with wind chills as low as -50 degrees. Additionally, Cold Weather Advisories and Extreme Cold Watches are in effect in many areas.

High temperatures across much of the country will be 20-30 degrees below average. The northern Plains and Upper Midwest will experience subzero temperatures, while the Rockies and central Plains will see single digits and teens. The East Coast and parts of New England are also in for a cold blast, with temperatures in the teens and 20s. Meanwhile, the southern Plains and Southeast will see highs in the 20s and 30s.

This extreme cold will continue to grip the nation, with life-threatening wind chills expected to persist in the Rockies, northern Plains, and Upper Midwest through Tuesday morning.