Ready for our December 2020 weather forecast? This month begins the “meteorlogical winter.” It’s going to be a chilly start in much of the United States and Canada. Let’s take a look at what’s in store.
Overall, December will bring near- or colder-than-normal temperatures across most of the United States, especially the eastern states into the mid-Altantic and Southeast. However, expect significantly warmer-than-normal temperatures in the Heartland, Southern Plains, Intermountain region, Southerwest, Pacific Northwest, and Alaska.
Western and northern Canada will have near-normal temperatures, on average, while cold weather will predominate in eastern and central provinces. Precipitation will be much below normal from Georgia southwestward to Louisiana, from the Intermountain region southwestward to California, and on the Hawaiian islands of Kaua’i and Ni’ihau, but near or above normal elsewhere.
Holidays and Observances
Let’s spotlight a few special days!
On Wright Brothers Day—December 17—temperatures will soar in the western half of the United States and Canada, as mild temperatures dominate. Across the East, temperatures will crash, especially in the northeast states and Quebec, where they will not lift off at all.
Winter officially starts with the solstice on December 21, with the only weather of note being a New England snowstorm.
If you are traveling on or around Christmas or Boxing Day, you can expect the potential for travel issues in those same areas, with mostly light snow falling, but dry or rainy weather elsewhere.
New Year’s Eve will be cold but dry in much of the United States, although snowy periods are likely from the Appalachians northward to the Great Lakes and westward to the Intermountain region and some rain will fall in Texas and the Pacific Northwest. Most areas in Canada will have skiffs of snow, but not boatloads.
Weather and Climate Patterns
As for the upcoming winter, we are entering Solar Cycle 25, which is expected to bring very low solar activity. Although low levels of solar activity have historically been associated with cooler temperatures, on average, across Earth, we believe that recent warming trends will dominate in the eastern and northern parts of the United States in the coming winter, with below-normal average temperatures limited to the western portion of the nation. Temperatures will average above normal in most of Canada, except for Atlantic Canada and the Prairies, where below-normal temperatures are expected.
As we move toward the winter, watch for any changes in the ENSO pattern (the El Niño-Southern Oscillation, which is based on temperatures in the Pacific Ocean), where we expect a weak La Niña to develop. If the La Niña were to be stronger, colder temperatures would likely prevail across the northern Plains and southern Ontario. If we instead have more neutral conditions or an El Niño, California would experience heavier rainfall while the Canadian Prairies would have milder temperatures.