Several waves of arctic air could keep temperatures below zero in parts of the Midwest and Northern Plains. (Watch the forecast from Dec. 30 at 4 p.m. in the video player above.) While this polar vortex event will not affect Northern California,

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.

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

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is about to bring even harsher arctic blast to nearly 300 million Americans starting this weekend. Maps show where and when the cold front will arrive.

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.

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