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

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.

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

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.

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.

A new blast of Arctic air sweeping from north to south will bring bone-chilling temperatures to millions of Americans this weekend and next week.

Over 120 million Americans will face extreme cold, with temperatures potentially reaching minus 40 degrees Celsius. Meteorologists warn that it will be colder than in Greenland. Due to the frigid weather,

AVERAGE LOW FOR JANUARY 18th: 15° SATURDAY’S SUNRISE: 7:32 AM SATURDAY’S SUNSET: 5:04 PM Elmira, N.Y. (WETM) – A polar vortex brings in freezing temperatures into the work week. Otherwise, we will see a lot of sunshine for the work week.