So what's causing these temperature extremes?
The polar vortex is a mass of winds that form over the Arctic each winter, and tend to move in a circular motion around the region, according to NASA. This year, however, a few factors caused the vortex to dip south, like the jet stream moving further south than usual and a low-pressure system forming over Canada, according to the video.
As this animation progresses from early December 2013 to early January 2014, you can watch the polar vortex -- represented by the purple colors -- bend southward over time. It features data collected by NASA's Atmospheric Infrared Sounder Mission instrument, and shows temperatures at 3,000 feet above the Earth's surface.