Alerts for cold weather are in effect for nearly half of the U.S. population, running from the northern Plains to the Gulf Coast and the Rockies to the Southeast.

Another blast of winter weather is expected in parts of the U.S. in the coming days, including bone-chilling wind in the Northern Plains and unusual snow and ice in the Gulf Coast area

More than 120 million Americans are expected to face extreme cold, with temperatures potentially dropping as low as minus 40 degrees Celsius. Meteorologists have warned that it will be colder than in Greenland.