When Does Winter Start? Snow, Polar Vortex, Cold Weather To Hit US This Week

It's still technically fall in the Northern Hemisphere, even if it certainly feels like winter in the United States' Northeast this week, as cold air and snow hit the coast.

A snow storm that pummeled the Midwest Sunday night with up to a foot of snow and caused two deaths has made its way east, blanketing parts of the Northeast with a few inches of snow. Boston saw just about an inch of snow, while small pockets in New Hampshire and Maine saw up to eight inches.

Yet, in astrological terms, winter doesn't officially begin until Dec. 21. The winter solstice, which signals the beginning of the season, will officially take place that day at 5:44 a.m. EST. After that, days will continually get longer until the spring equinox on March 20.

But many are already celebrating the winter weather that has already arrived. Ski resorts in New England, for instance, are thrilled with this December's snowfall compared with 2015, reported the Boston Globe Monday. At some resorts, the total snowfall for December has already doubled what they saw in 2015.

The cold weather is expected to continue throughout the week, with frost possible as far south as Atlanta, USA Today reported. The region is bracing for a Polar Vortex, a large area of high pressure and cold air.

"It may not set records, but it will be really, really cold," Bruce Sullivan, senior meteorologist at the National Weather Service's Weather Prediction Center told USA Today. "The thing is, it's not even winter yet."

High temperatures could be 20 or 30 degrees below the usual highs as the vortex expands south, UPI reported. That means Chicago could see single-digit temperatures by Thursday and New York City could see highs in just the 20s from midweek through the weekend. The Red Cross has a number of helpful tips for staying safe during cold, including keeping space heaters at least three feet from all flammable materials and remembering to wear many layers of light clothing.