Ontario's October forecast for 2026 has officially arrived and here's what to expect

With fall just around the corner, Ontario is getting its first glimpse at what the upcoming season could have in store, and the latest long-range forecast is calling for a cooler and wetter-than-average September before temperatures rebound closer to normal in October.

The Old Farmer's Almanac released its October weather forecast for southern Ontario this week, and it is expected to be much more balanced than September, with temperatures returning close to seasonal averages. 

Sunny and chilly conditions are expected across the province between Oct. 1 and 6. From Oct. 7 to 14, rainy periods will likely be followed by warm conditions, before chilly temperatures sweep in once again. 

The period between Oct. 15 and 21 is expected to bring lots of precipitation to southeastern Ontario, as well as rain and snow showers in the west. From Oct. 22 to Halloween, the east is anticipated to see a few showers, while it'll likely be sunny and warm in southwestern Ontario. 

Overall, the average temperature in southern Ontario in October is expected to be 11 C, which is in line with what is typically observed that month. Precipitation totals will likely reach 90 mm, which is 40 mm above average in the east, and 20 mm below average in the west. 

Before we jump the gun, though, the Old Farmer's Almanac has also released its weather outlook for September. Between Sept. 5 and 8, thunderstorms are expected across the province, while temperatures will remain warm. 

The weather will continue to fluctuate drastically throughout the rest of the month, bringing lots of showers, followed by sunny and cool conditions. The month is expected to close out on a rainy and chilly note, with an average temperature of 15 C (1 C below average). 

Overall, the Old Farmer's Almanac notes in the Canadian edition of its 2026 fall forecast that the country is headed for a milder fall. While September is gearing up to be cooler than normal, temperatures will rebound just in time for October. 

The report also predicts that most of Canada will record above-average precipitation this fall, including in southeastern Ontario, where rainfall will be "well above average," and southwestern Ontario, which is expected to see "slightly above average" rainfall.