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

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

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

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

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

Sudden stratospheric warming is expected to keep a weakened vortex splintered, plunging the region back to record-breaking ...

Scientists have created the highest resolution map of the dark matter that threads through the universe—showing its influence ...

The majority of the United States will experience chilling temperatures due to a blast of arctic air from Canada. The Midwest, Mid-Atlantic and Southern U.S. are expected to see below-freezing ...