(CNN) Think of it as January in November.

A blast of Arctic air is sweeping the eastern two-thirds of the United States, moving millions to bundle up against freezing temperatures earlier than usual and putting people as far south as Texas at risk for snow and ice.

About 70% of the US population is expected to see temperatures at or below freezing by Wednesday morning, and hundreds of records are expected to fall with temperatures generally 20 to 40 degrees below normal.

Travel could be tricky especially in 15 states from Texas to New England, where snow and ice could accumulate. Elsewhere, parts of the Deep South are under freeze watches, warnings or advisories, including South Texas and the Florida Panhandle.

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