Ontario's fall forecast for 2026 has officially arrived and here's what's in store

Ontario's fall forecast for 2026 has officially arrived, offering an early glimpse of what the upcoming season could bring, and after a summer that's so far brought back-to-back heat waves and smoky skies, it looks like Mother Nature will be keeping us on our toes.

The Old Farmer's Almanac released the Canadian edition of its 2026 fall forecast this week, noting that the country is headed for a milder fall overall. Although warmer-than-average temperatures are expected across the majority of provinces and territories, cooler weather is expected in certain pockets.

In southern Ontario specifically, September is shaping up to be cooler than normal before temperatures rebound and return close to normal in October.

Precipitation-wise, it's looking like most of Canada will have above-average precipitation this fall, including in southeastern Ontario, where rainfall will be "well above average," and southwestern Ontario, which will likely experience "slightly above average" rainfall.

According to Almanac's map, Ontario's upcoming fall season can be characterized as "cool and wet," joining the likes of other regions, including eastern Quebec, parts of Nunavut, and southern B.C.

Photo: Old Farmer's Almanac. 

The Almanac notes that its long-range forecasts are derived from three pillars, namely solar science, climatology, and meteorology. The publication watches the sun's activity, studies long-term weather patterns, and tracks changes in the atmosphere to piece together what the upcoming season will look like.

The Almanac has also released its August long-range weather forecast for southern Ontario, predicting that the average temperature will be 20 C next month, which is 1 C below average in southeastern Ontario, and 1 C above average in the west.

Scattered thunderstorms are expected throughout the month, and temperatures will vary slightly by period. Warm temperatures are expected between Aug. 1 and 9, Aug. 17 to 26.

Between Aug. 10 and 16, cool but sunny conditions are expected in southeastern Ontario, as well as between Aug. 27 and 31 in southwestern Ontario.

Overall precipitation totals are anticipated to hit 125 mm, which is 70 mm above average in the east and 20 mm above average in the west.