Some sates saw subzero temps. Here's how cold it got in all states, and why it got so cold.

Over the next 10 days, scientists say, changes in the stratosphere will upend weather patterns and set the stage for a cold, snowy December across parts of the Northern Hemisphere.

Meteorologists have recently noticed a strange kind of winter pattern. Researchers at NOAA found that parts of the atmosphere are lining up in ways that they haven’t spotted for many decades. These ...

A strong polar vortex doesn't cause cold weather — it does the opposite. Here's what to know about polar vortices, how they ...

The Upper Midwest and Northern Plains have been hit by Canada's freezing temperatures. On Thursday, Dec. 4, wind chills ...

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 ...

Early-season stratospheric warming events spark hype around frigid temperatures. Learn the myths and the science about the ...

An Arctic blast could bring freezing temperatures and heavy snow to Kentucky around Thanksgiving weekend. A "sudden stratospheric warming" event may disrupt the polar vortex, potentially causing ...

A rare stratospheric warming event high above the Arctic could disrupt the polar vortex and send colder air toward Texas in ...

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 ...