A polar vortex dipping down from Siberia is bringing a cold front with frigid temperatures to millions Americans. See maps of ...

New research reveals the Arctic is changing fast as permafrost regions are warming, forests are stressed, and flooding is ...

Extreme cold could expose residents of several states to conditions like hypothermia and frostbite over the weekend.

"The most climate-stressed regions all contained permafrost, which is vulnerable to thaw as temperatures rise," researcher Sue Natali said.

Life in the world's coldest ... If you can't see the map above, click here. AccuWeather's lead long-range meteorologist, Paul Pastelok, said: "The first Arctic high-pressure area will sink ...