It's a cold air outbreak that some experts say is happening more frequently, and paradoxically, because of a warming world.

If you're braving the cold during the polar vortex that's skating across much of the US right now, you're probably looking ...

A huge swath of the U.S. was blasted with ice, snow and wind on Monday as the polar vortex that dipped south over the weekend kept much of the country east of the Rockies in its frigid grip, making ...

A huge swath of the U.S. is being blasted by ice, snow and wind, as the polar vortex that dipped south over the weekend is keeping an area stretching from the Rocky Mountains to the coast of Maine in ...

The polar vortex of ultra-cold air usually spins around the North Pole, but it sometimes plunges south into the US, Europe ...

A polar vortex is currently hitting the United States, with schools closed in many areas and at least four deaths caused by ...

A surveillance camera shakes as a magnitude 6.8 earthquake rocks the northern foothills of the Himalayas near one of Tibet's ...

A polar vortex has triggered freeze warnings across Texas, leading to dangerous conditions for people and infrastructure.

It's a term you hear every couple of winters, when we get stuck in the coldest of cold patterns – polar vortex. But what exactly is it?

The polar vortex has triggered freeze warnings and advisories across Texas, threatening human safety and infrastructure.