The Old Farmer’s Almanac long-range weather outlook for September offers a region-by-region look at what the month ahead may bring across the United States.
As a long-range outlook, the forecast describes broad regional patterns rather than exact day-to-day conditions. The Almanac divides the country into zones and outlines whether temperatures and precipitation are expected to trend above or below historical averages.
The publication says its long-range forecasts combine solar science, climatology and meteorology. Its method compares solar patterns and historical weather conditions with current solar activity, while also considering climate data and large-scale signals such as El Niño and La Niña to predict broader temperature and precipitation trends.
Here’s a regional overview of what conditions are likely for September, according to the publication:
September begins with showery and cool conditions through September 7, followed by a sunny but still cool period from September 8 to 11. Rainy periods are expected before sunshine returns from September 12 to 19, while showers and cool conditions are forecast for the remainder of the month.
The Almanac forecasts a temperature of 59 degrees, 2 degrees below average, with 5.5 inches of precipitation, around 2 inches above average.
Atlantic Corridor
The Atlantic Corridor is expected to see scattered thunderstorms from September 1 to 12, with warm conditions giving way to cooler weather. Scattered showers are forecast in the north from September 13 to 23, while the south remains sunny, before isolated showers and cool conditions affect the region during the final week.
Precipitation is forecast at 3 inches, about 1 inch below average, while the temperature is expected to average 68 degrees, 1 degree below normal.
Appalachians
September starts sunny and warm in the Appalachians before scattered showers bring cooler conditions from September 7 to 12. From September 13 to 23, isolated showers are expected in the north while the south remains sunny, with cool temperatures turning warmer. Showers and cool weather follow from September 24 to 27, before the month ends with showers in the north, sunshine in the south and milder conditions.
The region’s September temperature is forecast at 63 degrees, 2 degrees below average, with precipitation around 2 inches below average.
Southeast
The Southeast outlook calls for sunny and mild conditions to open September. Thunderstorms are expected before sunshine returns from September 8 to 18, accompanied by cooler weather. Another sunny and mild stretch follows through September 24, with the month ending sunny as cool conditions turn warmer.
The Almanac forecasts a temperature of 74 degrees, 1 degree below average, and 2 inches of precipitation, about 3 inches below average.
Florida begins the month with scattered thunderstorms and conditions turning from warm to cooler through September 11. From September 12 to 20, the north is expected to be sunny while the south sees thunderstorms, with mild temperatures across the region. Sunshine is forecast to continue in the north through the end of the month, while isolated thunderstorms remain possible in the south.
Precipitation is forecast at 7.5 inches, with the north 2 inches below average and the south 2 inches above average. The Almanac forecasts a temperature of 80 degrees, 1 degree below average.
Lower Lakes
The Lower Great Lakes region is expected to start September sunny, with cool conditions turning warmer through September 8. Rain and cooler weather are forecast from September 9 to 11, followed by periods of rain in the east and sunshine in the west through September 16. Showers are expected from September 17 through the end of the month, with cool temperatures becoming milder.
The Almanac forecasts an average September temperature of 60 degrees, 2 degrees below normal, and 3 inches of precipitation, considered average.
Ohio Valley
September begins with scattered showers in the Ohio Valley, with warm weather turning cooler through September 9. Sunny conditions follow from September 10 to 20 as cool temperatures become warmer. The final 10 days are expected to bring scattered showers in the east and sunshine in the west, with cool conditions across the region.
September’s temperature is forecast at 66 degrees, 2 degrees below average, with precipitation average in the east and 2 inches below average in the west.
Deep South
The Deep South begins September with sunshine followed by showers, while cool conditions turn warmer through September 8. Sunny and cool weather is expected from September 9 to 14, followed by sunny and warm conditions through September 23. Isolated showers are forecast during the final week, with cooler weather in the north and mild conditions in the south.
The region’s temperature is forecast at 76 degrees, 1 degree below average, with precipitation around 2 inches below normal.
Upper Midwest
The Upper Midwest outlook starts with sunshine and a turn toward very warm conditions through September 6. A few showers and chilly weather are forecast from September 7 to 10, followed by sunshine and then showers through September 16. Rainy periods and cool conditions are expected from September 17 through the end of the month.
The Almanac forecasts a temperature of 57 degrees, 2 degrees below average, and 3.5 inches of precipitation, a half inch above average.
Heartland
The Heartland is expected to begin September sunny and warm before a few showers alongside chilly conditions from September 6 to 9. Sunshine returns from September 10 to 16 as temperatures turn warmer, followed by thunderstorms through September 19. Sunny and hot weather is forecast from September 20 to 23, before isolated thunderstorms and cooler conditions close the month.
The Almanac predicts an average September temperature of 68.5 degrees, a half-degree above normal, with 1.5 inches of precipitation, about 2 inches below average.
The region begins September sunny and warm before a few thunderstorms and hot conditions develop from September 5 to 9. Sunny weather follows from September 10 to 19, with cool conditions turning hot. From September 20 to 25, the north is forecast to remain sunny while the south sees isolated thunderstorms, with hot weather across the region. Rainy periods, some heavy, are expected during the final five days as temperatures turn cooler.
Precipitation is forecast at 4.5 inches, 1 inch above average, while the temperature is expected to average 78 degrees, also 1 degree above normal.
High Plains
September opens with sunshine and very warm conditions in the High Plains. From September 6 to 14, the north is expected to remain sunny while isolated thunderstorms develop in the south, with the region turning cooler. A few showers followed by sunshine are forecast from September 15 to 21, accompanied by warmer weather. Isolated showers and warm conditions are then expected through the end of the month.
The Almanac forecasts a temperature of 65 degrees, 2 degrees above average, and precipitation a half inch below normal.
Intermountain Region
The Intermountain Region is forecast to begin September with sunshine in the north and isolated thunderstorms in the south, with warm conditions through September 8. Sunny weather follows from September 9 to 11, with hot conditions in the north and warm weather in the south. From September 12 to 21, sunshine is expected before a few showers develop, while the north remains cool and the south warm. The month ends with sunshine followed by rainy periods and a continuing north-south temperature divide.
September precipitation is forecast at 1.5 inches, a half inch above average. Meanwhile, the temperature forecast is 64.5 degrees, 1 degree below average north and 2 degrees above average south.
Desert Southwest
The Desert Southwest begins September with a few thunderstorms and cool weather in the east, while the west remains sunny and warm. Sunny and warm conditions are forecast across the region from September 4 to 13. Isolated thunderstorms then give way to sunshine and very warm weather through September 22, before rainy periods and cooler conditions arrive from September 23 to 26. The final four days are expected to be sunny and cool.
The Almanac forecasts an average temperature of 81 degrees, 1 degree above normal, with precipitation around the historical average at 1 inch.
Pacific Northwest
The Pacific Northwest starts September sunny and very warm, with those conditions expected to last through September 10. Showers followed by sunshine and cooler weather are forecast from September 11 to 17. Rainy periods and chilly conditions are then expected from September 18 through the end of the month.
September’s temperature is forecast at 61 degrees, 1 degree below average, with 4.5 inches of precipitation, around 3 inches above average.
Pacific Southwest
The Pacific Southwest is expected to begin the month with sunny and warm conditions. From September 10 to 14, the region will see plenty of sunshine, with cool temperatures in the north and hot weather in the south. A few showers are forecast in the north from September 15 to 22, while the south remains sunny, before isolated showers and cool conditions affect the region during the final week.
The Almanac forecasts a temperature of 72 degrees, considered average, with 0.3 inches of precipitation, about 0.2 inches above average.
Alaska begins September with rain and snow showers in the north, a few showers in central areas and rainy conditions in the south, with temperatures turning cooler through September 12. Flurries are forecast in the north from September 13 to 18, while the east and west see a few showers and chilly conditions. Periods of rain and snow are expected in northern and central Alaska from September 19 through the end of the month, with a few showers in the south and cold conditions.
The Almanac forecasts temperatures 2 degrees below average, with precipitation below normal in both the north and south.
Hawaii’s outlook begins with scattered showers and warm conditions through September 8. Heavy rain is possible in the west from September 9 to 11, followed by heavy rain in the east and sunshine in central and western areas through September 14. Isolated showers are then forecast in the east, while central and western areas remain sunny and temperatures turn hot. The Almanac flags a tropical storm threat from September 23 to 25, before showers and warm conditions close the month.
September precipitation is forecast at 3.3 inches, with rainfall 4 inches above average in the east and west but a half inch below average in central areas. The temperature is forecast to be 81 degrees, a half degree below average.
Contact Newsweek editors for this story: Kate Nalepinski and Anthony Murray.