CNN: A rare icy weather pattern is walloping virtually the entire United States at once.
"It's very unusual," CNN meteorologist Dave Hennen said Monday. "This literally spreads across the entire U.S., and we're 12 days from the official start of winter."
Temperatures have plunged below freezing in parts of California and Nevada, including Las Vegas. Wind chills are 40 below zero in the Midwest. Snow and ice have blanketed a large swath of the Northeast, all the way up to Maine.