Ontario (Toronto)
September
Weather in Ontario for September 2025
Your guide to Ontario weather in September - trends and predictions
Until now, September 2025 in Ontario is slightly cooler than the historical average by -1.9 °C.
Expect cooler weather in the next days in Ontario with the forecast suggesting a temperature of 22.5 °C, lower than the historical average.
In general, the average temperature in Ontario at the beginning of September is 24.9 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.3 °C by the end of September.
The climate of Ontario in September is notably wet, with an average of 12 rainy days, and a total of 57.3 mm of precipitation.
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Temperatures
Rain 🌧️
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18
Dry days
12
Rainy days
0
Snow days
22°/15°
Temperatures
16 km/h
Avg max wind
67 %
Avg humidity
Ontario Weather September
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What’s the Weather Like in Ontario This September?
Discover the average temperatures and weather trends across Ontario’s cities this September.
Temperatures trend during September in Ontario
See the weather trend as well as the moving average line
September weather in Ontario day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Sunny | 25° /15° | 0 mm | 6 | |
| 2 Sept. | Sunny | 24° /15° | 0.3 mm | 6 | |
| 3 Sept. |  Partly cloudy | 27° /16° | 0.2 mm | 6 | |
| 4 Sept. | Partly cloudy | 26° /16° | 3.6 mm | 6 | |
| 5 Sept. |  Overcast | 26° /17° | 0.9 mm | 6 | |
| 6 Sept. | Partly cloudy | 25° /17° | 2.4 mm | 5 | |
| 7 Sept. |  Patchy rain possible | 21° /15° | 2.3 mm | 5 | |
| 8 Sept. |  Cloudy | 23° /13° | 1.6 mm | 5 | |
| 9 Sept. | Sunny | 23° /13° | 0.7 mm | 6 | |
| 10 Sept. | Partly cloudy | 23° /14° | 0 mm | 6 | |
| 11 Sept. | Overcast | 24° /16° | 0 mm | 6 | |
| 12 Sept. | Partly cloudy | 24° /16° | 1.1 mm | 6 | |
| 13 Sept. | Patchy rain possible | 23° /14° | 0.3 mm | 5 | |
| 14 Sept. | Patchy rain possible | 24° /14° | 0.2 mm | 6 | |
| 15 Sept. | Sunny | 22° /14° | 0.5 mm | 6 | |
| 16 Sept. | Sunny | 25° /15° | 0 mm | 1.3 | |
| 17 Sept. | Sunny | 24° /16° | 0 mm | 1.3 | |
| 18 Sept. |  Mist | 25° /15° | 0 mm | 1.2 | |
| 19 Sept. | Sunny | 21° /13° | 0 mm | 1.3 | |
| 20 Sept. | Sunny | 17° /13° | 0 mm | 0 | |
| 21 Sept. | Patchy rain possible | 25° /16° | 0.5 mm | 4 | |
| 22 Sept. | Sunny | 29° /21° | 0 mm | 6 | |
| 23 Sept. | Sunny | 26° /19° | 0.1 mm | 6 | |
| 24 Sept. | Patchy rain possible | 24° /19° | 1.9 mm | 5 | |
| 25 Sept. | Patchy rain possible | 23° /17° | 0.6 mm | 4 | |
| 26 Sept. | Patchy rain possible | 19° /15° | 2.1 mm | 4 | |
| 27 Sept. | Patchy rain possible | 20° /13° | 0.6 mm | 4 | |
| 28 Sept. | Patchy rain possible | 18° /15° | 0.3 mm | 4 | |
| 29 Sept. | Sunny | 19° /14° | 0 mm | 5 | |
| 30 Sept. | Sunny | 19° /11° | 0 mm | 5 | |
| Next | |||||
Important Notice
Our weather forecast for Ontario in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Ontario forecast closer to your planned date for the most up-to-date weather information.
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Ontario in September - FAQ
What are the expected maximum and minimum temperatures in Ontario during September?
During September, expect a variety of temperatures with highs around 22° and lows near 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Ontario during September?
Moderate rainfall is anticipated in Ontario during September, with a total of 57.3 mm spread over approximately 12 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Ontario during September?
The average wind speed in Ontario during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Ontario
Explore the daily rainfall trends and prepare for Ontarios September weather 💧
UV exposure in Ontario during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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