The polar vortex's blast of Arctic air from Canada brought the season's coldest weather to the majority of U.S. The vortex is forecast to provide frigid weather as it continues to bring sub-zero temperatures to the Midwest, Mid-Atlantic and plunge deep into the South.

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.

Dangerous temperatures are sweeping the country, with 100 million people from the Plains to the Northeast feeling the chill. Even those in the South will see some effects. Several cities have already declared weather emergencies,