In some areas, the weather could feel more like May than late December.
Snow in Hawaii isn't as unusual as you might think, but some northern U.S. cities are seeing significant delays to the start of their winter season.
A wide swath of the western U.S. may be in for below-average temperatures as forecasts suggest an Arctic blast is looming.
The agency’s Climate Prediction Center expects warmer-than-average conditions for much of the contiguous U.S.