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.

This week will bring a north/south split in terms of temperature and weather, according to the Met Office, with Northern Ireland and the northern half of the country seeing cloudy weather with outbreaks of patchy rain and between 9C and 12C, while the central and southern areas drier and between 5C and 8C.

A polar vortex is set to impact much of the US. Click here for the latest update. A polar vortex is forecasted to blanket most of the continental United States in the coming week, with parts of the Deep South expected to see freezing temperatures.

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.

An arctic blast will send temperatures across the United States plummeting as bitterly cold air that originated in Siberia will arrive from Canada by week’s end, bringing with it dangerously cold wind chills for millions of Americans.