In some states the wind chill may fall below -50 F.

The National Weather Service warned of "life-threatening cold" into Tuesday, with temperatures in northeastern Montana ...

States across the central and eastern U.S. are under extreme heat watches and warnings as the areas face a dangerous heat wave throughout the first half of the week, according to the National Weather ...

Wyoming and Colorado are bracing for a 25-degree temperature drop during a three-day period as cooler temperatures grip the West this week. The last few weeks have brought a range of unexpected ...