Fall Weather Forecast 2021: Autumn Keeps the Heat On

Read the Latest Forecasts for September and October 2021!

September 7, 2021
Fall Forest

Labor Day weekend is often considered the end of the summer season, but even in August we can’t help but wonder what sort of weather fall will bring. Here’s a sneak peek at what to expect this autumn!

2021 Fall Weather Forecast

Autumn, with its crisp nights, warm wool sweaters, and endless amount of pumpkin-flavored foods, officially begins with the autumnal equinox on Wednesday, September 22. Much of the United States and Canada will have appropriately cool temperatures on this day, although Florida will be on the hot side and mild to warm temperatures will prevail in most of the western states and provinces.

As for the rest of fall, temperatures across the United States will be warmer than normal in the Intermountain, Pacific Northwest, and Pacific Southwest regions and Alaska and below normal elsewhere. Precipitation will be above normal in the Northeast and Delmarva; from the eastern Great Lakes southwestward to the Tennessee Valley; and in southern Texas, the southern and central High Plains, the western Desert Southwest, the Pacific Southwest, and southern Alaska. They will be near or below normal elsewhere.

In Canada, autumn temperatures will be below normal in Quebec and Ontario and near or above normal elsewhere. Precipitation will be above normal from Atlantic Canada westward into eastern Ontario and below normal from central Ontario westward to the Pacific.

Want more weather? Find out what’s in store for your region in our 60-day Long Range Forecasts!

Autumn mountains, NC

Monthly Forecasts

October Weather: Cooler, With Spells of Spookiness

October temperatures will be cooler than normal, on average, across most of the United States and Canada, although the Intermountain region, Arizona, California, Oregon, Washington, southern Alaska, Kona (Hawaii), the Canadian Prairies, Yukon, and the Northwest Territories will have above-normal readings. Precipitation will be above normal in most of the eastern half of Canada and the United States and below normal in most other areas.

Child Health Day is October 4 across the United States, so make sure that your children have umbrellas if they are in New England, the Pacific Northwest, Alaska, or Hawaii, where rainy periods will dampen outdoor activities. Don’t be fooled by sunshine elsewhere—with cool temperatures the rule in most areas, your kids will need a jacket.

Leif Eriksson Day, celebrated on October 9 in the United States, recognizes the first European to set foot in North America, some 500 years before Columbus. Most areas will have appropriately chilly temperatures, with warmer air limited to Florida and California.

On October 11—Columbus Day and/or Indigenous Peoples’ Day in the United States and Thanksgiving Day in Canada—chilly temperatures will be the rule everywhere except for Florida and Ontario, where milder weather will prevail. Expect snow showers in interior New England, with rainy periods in most of the other states and dry weather in most of Canada.

Alaska Day is October 18, when cold temperatures will predominate, with sunshine in the south and snow showers in the central and northern portions of the 49th state.

United Nations Day, October 24, will see most of the United States united in cool temperatures, while most of Canada will unite with relatively mild weather. Most of both nations will have showers, with snowy periods in interior New England, Alaska, Ontario, and the Northwest Territories.

Warm temperatures will predominate in its namesake state on Nevada Day, October 29, with scattered showers mainly in southern areas.

Halloween—celebrated on Sunday, October 31, this year—is my favorite day of the year, as it is the one day when people don’t scream in terror when they see my face. The good news for trick-or-treaters is that dry weather will be the rule in most areas, although seasonally cool temperatures will predominate. Rain and snow showers will dampen bags and buckets in New England, the Appalachians, Lower Lakes, Upper Midwest, Intermountain region, and Alaska in the United States and from Atlantic Canada to Ontario and in British Columbia and the Northwest Territories in Canada.

September Weather: Late Summer Keeps the Heat On

In the United States, September temperatures will be hotter than normal, on average, from southern New England to eastern Virginia and in the Intermountain region, Pacific Northwest, and Alaska. Canada will also see higher temperatures from the Prairies to British Columbia and in Atlantic Canada, western Quebec, and northern parts of the nation. Elsewhere in both countries, temps will be near or below normal. 

Labor Day weekend will bring warm temperatures from the northeastern United States westward to the Heartland, with hot temperatures in southern Texas and the High Plains. Warm temperatures will be the rule in Ontario, with cooler weather elsewhere in Canada. Most areas in the United States and Canada will have showers or thunderstorms scattered about but nearly all of the time will be rainfree.

September 9 is Admission Day in California, where temperatures will be on the cool side with a few showers across northern and eastern parts of the state.

Patriot Day, as always, arrives on September 11 in the United States, where we’ll see the risk of a tropical storm moving from Florida into the mid-Atlantic states. Showers will be scattered in most other areas, although sunshine will prevail in the Upper Midwest, Heartland, and Desert Southwest and from Washington to California.

Sunshine will ease our aches and pains if we’re near the West Coast on September 12, Grandparents Day, but I’m afraid that my arthritis will be confirming scattered showers and thunderstorms in most other places.

September 17 is Constitution Day across the United States. While Texas and Florida will be hot, nearly everyplace else will be on the cool side. Sunshine will dominate most areas, with the rainiest weather in New England, the Lower Lakes, and the Heartland.

On the International Day of Peace, September 21, most of the United States and Canada will have rainy periods and cool temperatures—good weather for a peaceful day indoors!

The Winter Forecast Is Here!

Our annual Winter Forecast is out now—read it here!

For even more weather forecasts, pick up this year’s edition of The Old Farmer’s Almanac!


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