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

Swaths of the U.S. are expected to be hit with multiple intrusions of frigid air this month.

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

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

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 ...

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

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

The polar vortex is responsible for the record cold wave that is hitting parts of the U.S.

The polar vortex is a large upper-level, low-pressure area or circulation that typically resides above the Arctic Circle.

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

The phrase "polar vortex" has captured public attention and is now often misused to describe short-term bouts of frigid ...

A stretched polar vortex and persistent northern flow are fueling a remarkably cold and snowy start to winter across ...