Alliston
September
Weather in Alliston for September 2025
Your guide to Alliston weather in September - trends and predictions
In general, the average temperature in Alliston at the beginning of September is 25.1 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.3 °C by the end of September.
Alliston sees moderate rainfall in September, averaging 7 rainy days.
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23
Dry days
7
Rainy days
0
Snow days
23°/11°
Temperatures
16 km/h
Avg max wind
71 %
Avg humidity
Alliston in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  23° | 2  21° | 3 28° | 4 29° | 5 31° | 6  25° | 7  19° |
| 8  19° | 9  21° | 10 22° | 11 24° | 12  24° | 13 22° | 14  23° |
| 15 25° | 16 26° | 17 22° | 18 22° | 19 21° | 20  23° | 21 24° |
| 22 23° | 23 20° | 24 21° | 25 22° | 26 20° | 27 18° | 28 20° |
| 29 21° | 30 20° |
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Temperatures trend during September in Alliston
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. | Partly cloudy | 23° /12° | 0 mm | 6 | |
| 2 Sept. | Light rain shower | 21° /10° | 0.3 mm | 6 | |
| 3 Sept. | Partly cloudy | 28° /13° | 1 mm | 7 | |
| 4 Sept. | Patchy rain possible | 29° /15° | 0.4 mm | 7 | |
| 5 Sept. | Partly cloudy | 31° /16° | 0 mm | 8 | |
| 6 Sept. | Thundery outbreaks possible | 25° /17° | 12.4 mm | 6 | |
| 7 Sept. | Moderate or heavy rain shower | 19° /11° | 12 mm | 5 | |
| 8 Sept. | Overcast | 19° /8° | 0.3 mm | 5 | |
| 9 Sept. | Mist | 21° /9° | 3.2 mm | 5 | |
| 10 Sept. | Overcast | 22° /13° | 0 mm | 6 | |
| 11 Sept. | Light rain shower | 24° /13° | 0.9 mm | 6 | |
| 12 Sept. | Heavy rain | 24° /13° | 15.7 mm | 6 | |
| 13 Sept. | Overcast | 22° /12° | 0 mm | 6 | |
| 14 Sept. | Cloudy | 23° /12° | 0 mm | 6 | |
| 15 Sept. | Mist | 25° /10° | 0 mm | 6 | |
| 16 Sept. | Partly cloudy | 26° /12° | 0 mm | 7 | |
| 17 Sept. | Light rain shower | 22° /12° | 1.6 mm | 5 | |
| 18 Sept. | Mist | 22° /9° | 0 mm | 5 | |
| 19 Sept. | Partly cloudy | 21° /10° | 0 mm | 5 | |
| 20 Sept. | Sunny | 23° /9° | 0 mm | 6 | |
| 21 Sept. | Mist | 24° /14° | 5.6 mm | 5 | |
| 22 Sept. | Mist | 23° /13° | 1 mm | 5 | |
| 23 Sept. | Mist | 20° /12° | 21.3 mm | 5 | |
| 24 Sept. | Mist | 21° /13° | 0 mm | 5 | |
| 25 Sept. | Overcast | 22° /13° | 9.7 mm | 5 | |
| 26 Sept. | Partly cloudy | 20° /12° | 0 mm | 5 | |
| 27 Sept. | Overcast | 18° /11° | 0 mm | 5 | |
| 28 Sept. | Overcast | 20° /11° | 0 mm | 5 | |
| 29 Sept. | Mist | 21° /14° | 0 mm | 5 | |
| 30 Sept. | Mist | 20° /12° | 0 mm | 5 | |
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Important Notice
Our weather forecast for Alliston 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 Alliston forecast closer to your planned date for the most up-to-date weather information.
Alliston in September - FAQ
What are the expected maximum and minimum temperatures in Alliston during September?
Enjoy moderate daytime temperatures of up to 23° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Alliston during September?
Moderate rainfall is anticipated in Alliston during September, with a total of 62.1 mm spread over approximately 7 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Alliston during September?
The average wind speed in Alliston during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Alliston
Explore the daily rainfall trends and prepare for Allistons September weather 💧
UV exposure in Alliston during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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