There's a cold front across much of the U.S. – with temperatures in places like New Orleans at around 29 degrees and Houston about 34 degrees. This map from NASA tells us just how cold it was on Wednesday.
The image was captured at 11 a.m. EST. Here's NASA's explanation:
"The cold front that brought the Arctic air moved as far south as Florida, and stretched back over the Gulf of Mexico and just west of Texas. The image shows clouds behind the frontal boundary stretching from the Carolinas west over the Heartland. Farther north, a wide band of fallen snow covers the ground from New England west to Montana, with rivers appearing like veins. The GOES-East satellite image also shows wind-whipped lake-effect snows off the Great Lakes, blowing to the southeast. Meanwhile, Florida, the nation's warm spot appeared almost cloud-free."
Those low temperatures will persist today. Weather Underground notes temperatures 20 to 30 degrees lower than normal over the Mississippi Valley, the Ohio Valley, the Tennessee Valley and the Southeast.