Much below normal temperatures should persist across the eastern U.S. into early February before moderating slightly.

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

Major cities across the Northeast and Midwest are facing temperatures 10-20 degrees below average, according to forecasters.

A fresh blast of Arctic air is poised to spill across a wide swath of the United States, and the latest polar vortex map ...

A major storm system is set to bring "potentially catastrophic" winter weather across the southern U.S. this weekend, ...

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

The west half of the country, including the Midwest, will start to warm up. But that won't be the case for the East Coast.

"Bitter cold could linger through the end of the month," the Weather Prediction Center said in an update on Monday.

In the coming weeks, cold air will continue for parts of the U.S. thanks to the influence of the polar vortex.

Don't be fooled by the string of uneventful weather — the polar vortex is rebooting and will take another swing, or several, at the greater Philadelphia region, leading to a turbulent weather pattern ...