The polar vortex's blast of Arctic air from Canada brought the season's coldest weather to the majority of U.S. The vortex is ...

This blast of frozen temperatures is tied to a polar vortex... but what is that? Air spins around the notoriously cold North and South Poles. When the air is spinning fast, it's stable, but when it is ...

Like much of the U.S., Wisconsinites woke up Tuesday morning to bitter cold conditions. Many schools and colleges throughout the Milwaukee area closed as the area braced for the dangerous freezing ...