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.

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

Marylanders are bracing for the upcoming polar vortex, expected to bring temperatures into the single digits early this week. And state workers are out and getting ready for the freezing temperatures.

The polar vortex is expected to reach the Utah-Idaho border sometime in the late afternoon and evening Friday as it continues to move south. As it moves through parts of the state, it will produce small snow showers, bringing more snow to the region before drier conditions return.

These severe cold events occur when the polar jet stream – the familiar jet stream of winter that runs along the boundary between Arctic and more temperate air – dips deeply southward, bringing the cold Arctic air to regions that don’t often experience it.

AVERAGE LOW FOR JANUARY 19th: 15° SUNDAY’S SUNRISE: 7:32 AM SUNDAY’S SUNSET: 5:06 PM Elmira, N.Y. (WETM) – The polar vortex is here bringing in

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.

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.

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,