Christmas has passed, but the weather outside is still frightful. A snowstorm hit Delaware last week and was followed by a polar vortex dropping freezing temperatures in the region. The weather isn't getting any better.

Thanks to the polar vortex, it feels like one, too. Why is it so cold? The Philadelphia region was hammered Monday by the season’s first big storm, with some areas in Delaware a

With the Northern Hemisphere well into the winter months, it may seem like temperatures are cold enough already. However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is ...

A recent study explains how warmer temperatures at the top of the planet destabilize the jet stream and allow colder air to travel south.

January has already been colder than average in most states east of the Rocky Mountains for the first time in two years — and now, more frigid air is coming. A lobe of the polar vortex, a stormy ...

Most of the US will enjoy milder temperatures on Thursday, but the warmup will be brief as a polar vortex will send temperatures tumbling below freezing for most of the nation starting this ...

The polar vortex is a low-pressure system of cold air that swirls above Earth’s poles. There’s one over the South Pole in Antarctica – but for this story, we’ll be focusing on the one above the North Pole. Over the North Pole, the wind flows counterclockwise in the stratosphere around 16 to 50 kilometers (10-30 miles) high.

One of the key players in these dramatic shifts is something called the polar vortex. The polar vortex is a massive area of cold air located high in the atmosphere, typically spinning over the ...

A dangerous and potentially life-threatening stretch of cold weather has much of the U.S. on alert as a lobe of the polar vortex invades the nation and sends temperatures tumbling to levels not seen in years.

Much of the U.S. from the Rockies into the Northern Plains will see colder than normal temperatures starting Sunday into the coming week, including forecasted wind chills down to minus 40 degrees F (minus 40 degrees C) or colder in the Dakotas and northern Minnesota, National Weather Service Meteorologist Marc Chenard said.

People living "basically anywhere from the Rockies eastward" will see extremely cold temperatures over the next several days, a meteorologist says. That includes Kansas City, which is set to host a Chiefs playoffs game this weekend.

The temperature is predicted to be around 22 degrees during the swearing-in, the coldest since Ronald Reagan’s second inauguration.