Winter Storm

Sick of Winter? Most of U.S. Has Passed Coldest Time of Year

At a Glance

Climatologically speaking, the coldest time of the year has passed for much of the country.
The average date of winter's midpoint in the U.S. is Jan. 9-10.
As of. Jan 18, only five states have yet to reach their coldest average temperatures in a typical year.

If you're suffering from the winter blues and need some good news, here it is – the coldest time of the year has passed for much of the nation.

A map from NOAA's National Centers for Environmental Information provides a more detailed look at when the coldest day of the year, on average, occurs across the United States.

(MORE: When is the Coldest Time of the Year?)

This map shows the days of the Lower 48's coldest low temperatures during an average year, using 1981-2010 averages.
(NOAA/NCEI)

The Pacific Northwest, Southern California and southwestern Arizona typically deal with winter's harshest temperatures in mid-to-late December, based on 1981-2010 averages, while the eastern half of the country, as well as the higher elevations of the Rockies, experience the coldest average temperatures in January.

NOAA says this temporal discrepancy is due to increased snow cover later in the winter in the East and the Rocky Mountains. Increased snow cover reflects sunlight, keeping ground temperatures colder.

(MAPS: 7-Day Rain/Snow Forecast)

Alaskan climatologist Dr. Brian Brettschneider put together a map with the same data as NOAA but analyzed it a little deeper. In his map below, you can see the average date when winter temperatures bottom out in each state.

Oregon reaches its winter midpoint the earliest on Dec. 21, which was the first day of climatological winter this season. On Jan. 23, Michigan is the last state to see average temperatures bottom out.

(MORE: Portland, Oregon, May Be America's Most Winter-Fatigued City in 2016-17)

Keep in mind, however, not all locations in each state experience coldest average temperatures at the same time, and, of course, these dates can vary in any given year, based on the dominant atmospheric jet stream pattern in any winter.

In eastern Colorado, for example, the High Plains reach the winter midpoint before Dec. 22, while the Rockies in the western portion of the state bottom out later, between Dec. 29 and Jan. 11, depending on elevation. The overall average for all of the climate sites in Colorado is Dec. 28.

If you take the United States as a whole, the average date of winter's midpoint is Jan. 9-10, according to Brettschneider. Different dates are calculated when you look at just the Lower 48, which is Jan. 4, and when you include all of North America, which is Jan. 13.

(MORE: For the U.S, 2016 was the Second Warmest Year on Record)

The latest states to reach winter's midpoint are Alaska (Jan. 20), Maine (Jan. 20), Michigan (Jan. 23), New York (Jan. 19) and Vermont (Jan. 19).

MORE ON WEATHER.COM: 20 Coldest Large Cities in America