Old Farmer’s Almanac released its September weather predictions from Old Farmer's for the United States, calling for a month that starts showery and cool before turning briefly sunny, then settles back into showers and cool conditions. The forecast gives people in regions from the Atlantic Corridor to Florida and the Lower Great Lakes a broad regional outlook, not a day-by-day schedule.
The Almanac says its long-range forecasts combine solar science, climatology and meteorology. It compares solar patterns and historical weather conditions with current solar activity, then weighs climate data and large-scale signals such as El Niño and La Niña.
Atlantic Corridor and Appalachians
The Atlantic Corridor is expected to see scattered thunderstorms from September 1 to 12, with warm conditions giving way to cooler weather. After that, scattered showers are forecast in the north from September 13 to 23, while the south stays sunny, and the final week brings isolated showers and cool conditions. The region is forecast to average 68 degrees in September, or 1 degree below normal, with 3 inches of precipitation, about 1 inch below average.
The Appalachians open September sunny and warm, then shift to scattered showers and cooler conditions from September 7 to 12. From September 13 to 23, isolated showers are expected in the north while the south remains sunny. Showers and cool weather return from September 24 to 27, and the month ends with showers in the north, sunshine in the south and milder conditions. The September temperature is forecast at 63 degrees, 2 degrees below average, with precipitation around 2 inches below average.
The Southeast and Florida
The Southeast outlook calls for sunny and mild conditions to open September, then thunderstorms before sunshine returns from September 8 to 18, with cooler weather during that stretch. Another sunny and mild period follows through September 24, and the month ends sunny as cool conditions turn warmer. The region is forecast to reach 74 degrees, 1 degree below average, and receive 2 inches of precipitation, about 3 inches below average.
Florida begins the month with scattered thunderstorms and turns 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 continues in the north through the end of the month, while isolated thunderstorms remain possible in the south. Florida is forecast to have 80 degrees and 7.5 inches of precipitation, with the north about 2 inches below average and the south about 2 inches above average.
The Lower Great Lakes
The Lower Great Lakes region is expected to start September sunny and cool, then turn warmer through September 8. Across the month, the Almanac’s pattern points to a split country: some regions should run sunny and mild for stretches, while others are set for cooler and wetter weather at the same time. People in Florida and the Lower Great Lakes end up on opposite sides of that divide.
One region in the forecast is pegged at 59 degrees, 2 degrees below average, with 5.5 inches of precipitation, around 2 inches above average. That makes the practical takeaway simple: the Almanac’s outlook is not about exact daily timing, but about which regions are leaning wetter, drier, warmer or cooler as September unfolds.
