Weather Rarity: Snow in 49 States

Map showing snow cover in the United States on January 12. Darker blues represent deeper snow. Credit: NOAA

Get out the toboggans and winter gloves: There's snow on the ground in 49 out of 50 U.S. states – including Hawaii.

The only state that isn't at least partially a winter wonderland today is Florida, according to the National Weather Service (NWS). The agency estimates that 70.9 percent of the country is currently covered by snow.

"It's not typical," NWS public affairs officer James Peronto told LiveScience. The National Operational Hydrologic Remote Sensing Center, which tracks snowfall, doesn't keep statistics on the average snow cover, Peronto said. However, in December, an average of 35 percent of the United States had snow on the ground.

Snow in the Rocky Mountain states and Northeast is the norm in winter, of course. Even Hawaii often sees snowfall at high elevations. Right now, the top of the dormant volcano Mauna Kea on the island of Hawai'i is covered with 7 inches (18 centimeters) of snow. 

In this case, moisture from the Gulf of Mexico met up with cold air parked over the South. The result: Ice, sleet and plenty of the white stuff.

Snow in the eastern third of the United States is particularly unusual this year because La Nina (unusually cold ocean temperatures in the Pacific near the equator) normally keeps the jet stream in the northern regions of the United States, said David Robinson, the state climatologist of New Jersey and a professor at Rutgers University. 

But recently, the La Nina effect has been overshadowed by a negative North Atlantic Oscillation, an atmospheric pattern that brings cold and snow to the East and Southeast.

By Stephanie Pappas, LiveScience Senior Writer

 How to Live Safely in a Science Fictional Universe: A Novel