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.

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.

A major cold blast is in store for millions of Americans as a lobe of a polar vortex will bring brutally cold temperatures to nearly every American east of the Rockies.

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

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 of the country starting this weekend and stretching into next week,

Perfect time to hop on a plane and go somewhere south,” FOX Weather Meteorologist Britta Merwin said. “Like, really, really far south.”

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.