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

Cities across the U.S. are bracing for cold temperatures as a polar vortex arrives, bringing temperatures down to much below normal for mid-to-late January. Parts of Utah are on the "very western fringe" of a cold front that will bring in air from the Arctic.

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.

Some areas of the U.S. may see temperatures as low as -20 or -30 degrees early next week as arctic air from Siberia rolls in.

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.

Intense snowy wintry weather in the US has been fuelled by activity of the polar vortex, slipping down to engulf large parts of the country. Early January's winter storm prompted seven states to declare states of emergency,