Summer may end on a cooler note for parts of the U.S., with meteorologists suggesting that a weakened polar vortex could ...

The polar vortex is beginning to stir, signaling the first signs of seasonal change. Here's when to expect the first frost in ...

The polar vortex is stirring up, bringing the earliest hints that the seasons are changing. When will Wisconsin see its first freeze?

A rare and powerful stratospheric warming event appears to be unfolding high above the South Pole – and it could have a knock-on effect through the global weather system. Both of Earth’s poles are ...

Stratospheric warming high above Antarctica could cause the Southern Hemisphere’s polar vortex to weaken at an unusually fast pace over the coming weeks.

It's already a lot to endure frigid winter conditions, but what happens when we get an unwelcome visit from an even colder spell of air like a polar vortex? "A polar vortex is simply that: a vortex ...

From the polar vortex to sweltering summer heat, our team of forecasters gave every major city a weather-themed personality.