USA National Forecast

December Temperature Forecast Trends Colder In The East, But For How Long?

At a Glance

Big changes were made to December's outlook.
The East will start the month cold, while the West warms up.
It's uncertain when and how much the East may warm up later in the month.
Much of the nation may be drier, as well, with one exception.

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December temperatures may have a split personality both from west to east and early versus late in the month across the Lower 48 states.

A lingering chill: Much of the East from Georgia to the Great Lakes and Northeast may have a colder than average December, according to the updated outlook released Thursday by The Weather Company and Atmospheric G2.

The month will certainly start out cold in the East and South, lasting through at least the first, if not second, weeks of the month in most areas east of the Mississippi River.

But that isn't expected to last, based on longer-range computer model forecasts, according to Atmospheric G2 Vice President of Meteorology, Todd Crawford.

"It is a fairly easy call to say the back half of the month will be much warmer than the front half, it's just a question of degree," Crawford wrote.

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Western warmth: Meanwhile after a chilly start, much of the West into the Southern Plains is expected to have a warm December. That's particularly the case in the Great Basin and Desert Southwest.

The same jet stream pattern that may keep the East chilly may also keep much of the West warmer than average at least through mid-month. Beyond that, the Desert Southwest to the Southern Plains is most likely to remain warmer than average the rest of the month.

Another dry month: Much of the country will be either near or drier than average in December, according to the TWC/AG2 outlook.

That's particularly the case in the South, from Southern California to the northern Florida and the Carolinas.

Only a strip of the northern tier from Washington state to the northern Great Lakes may at least skew a bit wetter than average for the month.

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What December temperatures are typical: Average highs typically range from the 20s and 30s in the northern tier to the 50s, 60s and 70s in most of the South.

(MORE: See How Average Temperatures Grow Colder Through January)

Low temperatures usually plunge into the single digits, teens, and 20s in the northern states and Rockies. The South sees lows drop into the 30s, 40s, 50s and a few 60s in South Florida.