January should bring colder weather and snow chances to D.C. area.
On balance, the month should feature near-average temperatures and precipitation, a departure from the warm, dry December.
After our balmy and dry December, we may finally start seeing something more like winter in Washington in the weeks ahead. Our outlook calls for January to experience near-normal temperatures with near- to above-normal precipitation, as well as close-to-normal snowfall.
The road ahead could be very bumpy, with big swings in our weather, but it also looks to be different from the exceptionally warm and snowless December.
We predict temperatures to average between 36.5 and 38.5 degrees, which is within one degree of the most recent (1991-2020) 30-year average (37.5 degrees) and slightly colder than last year (38.6 degrees). For precipitation, we believe January can deliver between 2.5 and 3.5 inches of rain and melted snow, close to the average of 2.86 inches and wetter than last year’s 1.93 inches. We expect between 3 and 6 inches of snow, close to the average of 4.9 inches.
Normally, with La Niña conditions in the tropical Pacific, Washington experiences generally mild and dry conditions but, at least for this January, the computer weather models are favoring a strong chunk of cold air in western Canada to finally break free and advance in waves across the Lower 48. As a result, Washington is favored to see three cold pushes in the next two weeks.
Check out this visual buffet of temperature outlooks for the United States for the first half of January (top row) and the second half (bottom row) from different models:
https://www.washingtonpost.com/weather/2021/12/31/dc-january-weather-outlook-2022/?