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

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

With the warming of winter creeping in, extreme cold events were expected to fade, but that was not the case. Though certain cold spells were normal variations in climate that felt cold against a hot ...

Bitingly cold Arctic air keeps pummeling the U.S. with ruthless cold snaps—despite warming winters nationwide. A study explains why: the solution lies far above your head, in the upper atmosphere ...

Despite a warming climate, bone-chilling winter cold can grip parts of the U.S. In a study appearing in Science Advances, researchers found that two specific patterns in the polar vortex, a swirling ...

The polar vortex, a high-altitude ring of westerly winds that usually keeps Arctic air locked near the pole, is showing signs of unusual weakening. If that circulation falters or collapses, the result ...

High above the North Pole, in a slice of atmosphere rarely noticed and even less understood, a transformation is underway. Over the next 10 days, changes in the stratosphere will upend weather ...