THE GUARDIAN. It’s been so cold for so long in the midwest that the Great Lakes are almost completely covered with ice. The last time they came this close was in 1994, when 94% of the lakes’ surface was frozen. As of Thursday, ice cover extended across 88%, according to the federal government’s Great Lakes Environmental Research Laboratory in Ann Arbor.
‘That arctic vortex came down, and the ice just kept going,’ said George Leshkevich, a physical scientist with the federal lab.
More about the arctic vortex