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Canada weather

Weather in Alliston for September 2026

Your guide to Alliston weather in September - trends and predictions

    Temperatures

  • In general, the average temperature in Alliston at the beginning of September is 23.6 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.4 °C by the end of September.

    • Rain 🌧️

  • The climate of Alliston in September is notably wet, with an average of 11 rainy days, and a total of 104 mm of precipitation.

    • More

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Average dry days
19
Dry days
Average rainy days
11
Rainy days
Average snowy days
0
Snow days
Average temperatures
22°/12°
Temperatures
Average wind speed
16 km/h
Avg max wind
Average humidity
74 %
Avg humidity

Alliston Weather September

Move between months or click on a day
August
October
Mon.Tue.Wed.Thu.Fri.Sat.Sun.
1
Partly cloudy
23°
2
Light rain shower
22°
3
Partly cloudy
27°
4
Patchy rain possible
25°
5
Partly cloudy
28°
6
Thundery outbreaks possible
22°
7
Light rain shower
18°
8
Overcast
19°
9
Mist
22°
10
Overcast
22°
11
Partly cloudy
24°
12
Heavy rain
24°
13
Overcast
22°
14
Cloudy
24°
15
Mist
24°
16
Partly cloudy
25°
17
Light rain shower
23°
18
Fog
23°
19
Partly cloudy
21°
20
Sunny
22°
21
Mist
23°
22
Mist
24°
23
Mist
21°
24
Mist
20°
25
Overcast
22°
26
Partly cloudy
20°
27
Overcast
20°
28
Overcast
19°
29
Mist
22°
30
Mist
20°

Temperatures trend during September in Alliston

See the weather trend as well as the moving average line

September weather in Alliston day by day

Click on a date for more information
August October
Date Weather Temperatures Rain UV More
1 Sept. Partly cloudy
Partly cloudy
 23° /11° 0 mm 6
2 Sept. Light rain shower
Light rain shower
 22° /10° 0.2 mm 5
3 Sept. Partly cloudy
Partly cloudy
 27° /13° 0.7 mm 6
4 Sept. Patchy rain possible
Patchy rain possible
 25° /13° 24.9 mm 6
5 Sept. Partly cloudy
Partly cloudy
 28° /12° 0 mm 7
6 Sept. Thundery outbreaks possible
Thundery outbreaks possible
 22° /14° 8.3 mm 5
7 Sept. Light rain shower
Light rain shower
 18° /11° 10 mm 4
8 Sept. Overcast
Overcast
 19° /8° 0.2 mm 5
9 Sept. Mist
Mist
 22° /8° 2.2 mm 5
10 Sept. Overcast
Overcast
 22° /11° 0 mm 5
11 Sept. Partly cloudy
Partly cloudy
 24° /12° 0.6 mm 6
12 Sept. Heavy rain
Heavy rain
 24° /13° 10.5 mm 5
13 Sept. Overcast
Overcast
 22° /13° 0 mm 5
14 Sept. Cloudy
Cloudy
 24° /12° 0 mm 5
15 Sept. Mist
Mist
 24° /11° 0 mm 6
16 Sept. Partly cloudy
Partly cloudy
 25° /11° 0 mm 6
17 Sept. Light rain shower
Light rain shower
 23° /12° 1.1 mm 5
18 Sept. Fog
Fog
 23° /10° 0 mm 5
19 Sept. Partly cloudy
Partly cloudy
 21° /9° 0 mm 5
20 Sept. Sunny
Sunny
 22° /8° 0 mm 6
21 Sept. Mist
Mist
 23° /12° 3.8 mm 5
22 Sept. Mist
Mist
 24° /13° 16 mm 5
23 Sept. Mist
Mist
 21° /14° 14.2 mm 5
24 Sept. Mist
Mist
 20° /14° 4.9 mm 4
25 Sept. Overcast
Overcast
 22° /14° 6.5 mm 5
26 Sept. Partly cloudy
Partly cloudy
 20° /12° 0 mm 5
27 Sept. Overcast
Overcast
 20° /12° 0 mm 5
28 Sept. Overcast
Overcast
 19° /11° 0 mm 4
29 Sept. Mist
Mist
 22° /12° 0 mm 5
30 Sept. Mist
Mist
 20° /11° 0 mm 5
Next
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.
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Alliston in September - FAQ

What are the expected maximum and minimum temperatures in Alliston during September?

Enjoy moderate daytime temperatures of up to 22° and cooler nights around 12°. Ideal for a range of outdoor activities, from hiking to city tours.

How much rainfall should be expected in Alliston during September?

Significant rainfall exceeding 104 mm is expected in Alliston during September, occurring over more than 11 days. Preparing for wet conditions is recommended in your planning.

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 💧
Typically, Alliston has 11 rainy days in September with a total of 104 mm of rainfall.

UV exposure in Alliston during September

Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️

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Location coordinates Where is Alliston?

Get accurate weather forecasts for Alliston, located at latitude 44.15 and longitude -79.866. Stay updated with localized weather information tailored for Alliston.

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