A polar vortex dipping down from Siberia will bring a cold front with frigid temperatures to nearly 300 million Americans. See maps of the arctic blast.

Under the Rotunda of the U.S. Capitol, Donald Trump was again inaugurated, this time as the 47th president of the United States, capping a historic return to power that serves as resounding rebuke to the established political order.

According to the National Weather Service, a polar vortex will impact most of the country this weekend, here is what you need to know.

The most unusually cold air in the Northern Hemisphere will be over the United States early next week, bringing dangerously frigid conditions.

A rare winter storm is getting set to slam the Gulf Coast and South, with cities from Texas to Florida under Winter Storm Warnings.

A polar vortex is slated to sweep most of the continental US bringing winter storm warnings and a hazardous freeze to millions.

Snow and winds are likely to trigger flight cancellations and cause headaches for people traveling to DC for Inauguration Day.

A polar vortex is currently hitting the United States, with schools closed in many areas and at least four deaths caused by treacherous conditions.

A blast of Arctic air is set to cover much of the United States with temperatures below freezing starting on Friday and into next week, impacting millions of Americans in nearly all of the contiguous states.

People living "basically anywhere from the Rockies eastward" will see extremely cold temperatures over the next several days, a meteorologist says.

Despite a cold start to the day, most of the U.S. will experience seasonably mild temperatures on Thursday. However, dangerous changes are on the way as a polar vortex tightens its grip on the nation as sends temperatures tumbling below freezing starting this weekend.

Temperatures are expected to plummet over the weekend, bringing life-threatening conditions to large stretches of the United States. The polar vortex will send temperatures below freezing for much