As the days shorten and the leaves turn, we march on through autumn! Wondering what sort of weather the season will bring? Here’s a sneak peek at what to expect with our Almanac 2020 Fall Forecast.
2020 Fall Weather Forecast Summary
Autumn, with its cool, crisp nights, warm wool sweaters, and endless amount of pumpkin-flavored foods, officially began with the autumnal equinox on Tuesday, September 22.
Overall, November will bring milder-than-normal temperatures from central New England southward through Georgia; from the Great Lakes and Ohio Valley westward to Iowa; and in Texas, Oklahoma, the Pacific Northwest, and most of Hawaii. Near- or below-normal temperatures will be recorded elsewhere across the U.S. Most of eastern Canada will have above-normal temperatures, on average, with below-normal temperatures in most of the western provinces. Precipitation will be near or below normal in most of the U.S. and above normal in most of Canada.
Read more about the forecast for November holidays—including Thanksgiving!
Just when an early winter seems inevitable, October will roll in with milder-than-normal temperatures nearly everywhere—actually, make that “much warmer than normal” temps in the eastern two-thirds of the United States. But enjoy it while it lasts: As the leaves begin turning color and floating to the ground, above-normal rainfall will visit the Deep South and Southeast and range northeastward to New England, as well as predominate from central California northward through the Pacific Northwest. Most other areas will be dry or nearly so.
Autumn temperatures will be above normal in Atlantic Canada, southern Ontario, the Prairies, British Columbia, and the Yukon and below normal elsewhere across the Canadian commonwealth. Precipitation will be below or near normal in Ontario and the Prairies and above normal in nearly all parts of the other Canadian provinces.
And what about Halloween 2020? On October 31, the weather will be a treat across most of the United States, with dry weather and mild temperatures predominating. While the Prairies should be dry, most of Canada will have trickier weather, with showers across the south and snowy periods farther north.
September will bring cooler-than-normal temperatures, on average, which will linger through the month in most places, although temperatures for the month will average above normal in Florida, from the Intermountain region and Arizona westward to the Pacific, in Alaska and Atlantic Canada, and from the Prairies westward to the Pacific and northward to the Yukon.
September precipitation will be on the heavier side from southern New England southward to Georgia, from Pennsylvania southwestward to Louisiana, and in the Desert Southwest, southern Alaska, Atlantic Canada, Quebec, and portions of the Yukon and Northwest Territories. It will be near or below normal elsewhere.
A Preview of Winter Weather Ahead
Dare we even mention winter yet? (It is our job, after all.) Here’s a preview of what weather we’re expecting this year. For more, check out our new Winter Weather Forecast 2021!
As far as the upcoming winter goes, we will be 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. On the other hand, if we instead have more neutral conditions or an El Niño, California would experience heavier rainfall while the Canadian Prairies would have milder temperatures.