A collapse in the polar vortex is letting Artic air come here. What that means, and why it happens.

Niagara Falls has turned into a breathtaking icy landscape after a powerful polar vortex swept across the region, sending ...

Meteorologists warn that a stretched polar vortex could bring severe winter weather to much of the United States.

As the U.S. prepares to take on another bout of cold weather, the term "polar vortex" is getting thrown around. But what is ...

Much of the nation east of the Rocky Mountains is hunkered down for what could be the worst winter storm of the season.

A winter storm descending on the US is expected to deliver heavy snow and ice to more than 150 million people across roughly ...

After this weekend's snow storm moves out, cold Arctic air will move in.

Rising Arctic temperatures and melting sea ice could be causing cold air to flow into the Northern Hemisphere. But not all ...

The meteorologists said the polar vortex system is set up due north of Michigan over Canada's Hudson Bay. It's at least ...

The sudden blast may come as a shock to many Americans after a mostly mild start to winter, but that warmth may be partly ...

Similarly, wind chill temperatures measure how cold people and animals feel when outside, measuring the rate of heat loss ...

Temperatures could fall below -20 F across certain parts of North Dakota and Minnesota.