A polar vortex broke, and severe temperatures are set to dominate most of the United States, including the Midwest, in the coming days.

Thanks to the polar vortex, the first half of December will bring multiple waves of Arctic air to the U.S. Here's what to expect in Tennessee.

The Upper Midwest and Northern Plains have been hit by Canada's freezing temperatures. On Thursday, Dec. 4, wind chills ...

Some states are gearing up for subzero temperatures. Here's what to look out for.

Arctic wind patterns create a sort of wall around the pole that prevents frigid air from trickling southward. That wall that ...

The first of three rounds of bitter air has arrived, threatening record lows in cities from the Midwest to the Northeast.

A strong polar vortex doesn't cause cold weather — it does the opposite. Here's what to know about polar vortices, how they work.

As one blast of Arctic air pushes out to sea, already a new surge of cold air, driven by a breakdown of the polar vortex, is ...

Winter hasn't even officially started, but parts of the country are already bracing for what could feel like the deep freeze ...

As we head into the polar vortex, meteorologists are calling for up to a foot of snow in some parts of the U.S.

Some sates saw subzero temps. Here's how cold it got in all states, and why it got so cold.