Hopes for an extended summer might be dashed, as crisp autumn breezes and cozy sweater weather may be arriving a little earlier than expected across southern Ontario this year.
According to the Old Farmer’s Almanac long-range forecast for September 2026, the region is set to experience a cooler and noticeably wetter start to the fall season.
Overall, the average temperature for September is expected to sit at 15 degrees Celsius, which is roughly 1 C below seasonal norms. You’ll also want to keep your rain gear handy, as total precipitation is projected to reach 115 millimetres for the month, which is about about 25 millimetres higher than average.
The month will kick off from September 1 to 4 with cool conditions, bringing sunny skies to eastern Ontario while western areas experience scattered rain. Warmth will briefly return between September 5 and 8, though it will likely be accompanied by a round of late-summer thunderstorms.
Cooler temperatures will return from September 9 to 16, with lingering showers in the east and brighter, sunnier stretches in the west. Unsettled weather continues from September 17 to 23, starting with periodic rain before clearing into crisp, sunny afternoons.
To close out the month, the final stretch from September 24 to 30 promises to be the dampest and chillest, delivering a true autumn preview of rain and dipping temperatures.
Whether you are hoping to squeeze in a few final patio days or planning your early foliage outings, you can find the complete long-range breakdown on the Old Farmer’s Almanac website.
