Ontario
September
Weather in Ontario for September 2025
Your guide to Ontario weather in September - trends and predictions
In general, the average temperature in Ontario at the beginning of September is 26.4 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.6 °C by the end of September.
With an average of 4 rainy days, Ontario experiences minimal rainfall in September, ensuring that most days remain pleasantly dry.
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26
Dry days
4
Rainy days
0
Snow days
24°/14°
Temperatures
14 km/h
Avg max wind
64 %
Avg humidity
Ontario in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  24° | 2 22° | 3  29° | 4 30° | 5 30° | 6  29° | 7  21° |
| 8  22° | 9 22° | 10 23° | 11 24° | 12 26° | 13 22° | 14  24° |
| 15  25° | 16 26° | 17  23° | 18 23° | 19 24° | 20 23° | 21 24° |
| 22 22° | 23 21° | 24 21° | 25 23° | 26 23° | 27 19° | 28 18° |
| 29 20° | 30 20° |
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Temperatures trend during September in Ontario
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Mist | 24° /14° | 0.1 mm | 6 | |
| 2 Sept. | Mist | 22° /13° | 0.6 mm | 6 | |
| 3 Sept. | Partly cloudy | 29° /15° | 0 mm | 7 | |
| 4 Sept. | Partly cloudy | 30° /18° | 0 mm | 8 | |
| 5 Sept. | Partly cloudy | 30° /19° | 0 mm | 8 | |
| 6 Sept. | Thundery outbreaks possible | 29° /20° | 6 mm | 6 | |
| 7 Sept. | Light rain shower | 21° /15° | 4.2 mm | 5 | |
| 8 Sept. | Overcast | 22° /10° | 0 mm | 5 | |
| 9 Sept. | Overcast | 22° /12° | 1.4 mm | 5 | |
| 10 Sept. | Overcast | 23° /14° | 0 mm | 6 | |
| 11 Sept. | Overcast | 24° /15° | 0.1 mm | 5 | |
| 12 Sept. | Light rain shower | 26° /15° | 1.4 mm | 6 | |
| 13 Sept. | Overcast | 22° /13° | 0 mm | 6 | |
| 14 Sept. | Cloudy | 24° /13° | 0 mm | 6 | |
| 15 Sept. | Sunny | 25° /14° | 0 mm | 7 | |
| 16 Sept. | Overcast | 26° /14° | 0 mm | 6 | |
| 17 Sept. | Patchy light rain with thunder | 23° /15° | 0.9 mm | 5 | |
| 18 Sept. | Overcast | 23° /13° | 0 mm | 5 | |
| 19 Sept. | Partly cloudy | 24° /11° | 0 mm | 6 | |
| 20 Sept. | Partly cloudy | 23° /11° | 0 mm | 6 | |
| 21 Sept. | Mist | 24° /16° | 0 mm | 6 | |
| 22 Sept. | Mist | 22° /15° | 1 mm | 5 | |
| 23 Sept. | Mist | 21° /14° | 10.1 mm | 5 | |
| 24 Sept. | Sunny | 21° /14° | 0 mm | 5 | |
| 25 Sept. | Overcast | 23° /15° | 18 mm | 5 | |
| 26 Sept. | Overcast | 23° /15° | 0 mm | 6 | |
| 27 Sept. | Overcast | 19° /11° | 0 mm | 5 | |
| 28 Sept. | Patchy rain possible | 18° /14° | 0.1 mm | 4 | |
| 29 Sept. | Overcast | 20° /16° | 0 mm | 5 | |
| 30 Sept. | Mist | 20° /14° | 0 mm | 5 | |
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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.
Ontario in September - FAQ
What are the expected maximum and minimum temperatures in Ontario during September?
Enjoy moderate daytime temperatures of up to 24° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Ontario during September?
Expect minimal rainfall in Ontario during September, with a total of 12.4 mm over approximately 4 days. This minimal precipitation is unlikely to significantly impact plans.
What are the typical wind conditions in Ontario during September?
The average wind speed in Ontario during September is 14 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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