Just 72 hours ago, the official temperature in Chicago was -31°C. Right now, it's 0°C at O'Hare, the first time it's been above freezing since 11am Monday. Our 54-hour stretch of below-0°F temperatures was the 4th-longest such stretch. This has been an extraordinary few days, and it's just going to get weirder.
Bonus: The Tribune has a collection of satellite photos from the European Space Agency of our polar vortex.