easeweather.com
Units
°C
°F
Ontario
Forecast Today Tomorrow
more
California United States

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 33 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 30.1 °F by the end of September.

  • With an average of 4 rainy days, Ontario experiences minimal rainfall in September.

  • New! Chat with our AI weatherman - it’s amazing and free.
Average dry days
26
Dry days
Average rainy days
4
Rainy days
Average snowy days
0
Snow days
Average temperatures
28°/15°
Temperatures
Average wind speed
15 km/h
Avg max wind
Average humidity
55 %
Avg humidity

Ontario in September average weather

Move between months or click on a day
Select a date

You can click on date

Access Ontario weather forecasts with a simple click. Select any date for comprehensive insights on temperature, rainfall, and wind conditions.
Got it

Temperatures trend during September in Ontario

See the weather trend as well as the moving average line

September weather day by day

Click on a date for more information
Date Weather Temperatures Rain UV More
Sept. 1 Patchy rain possible
Patchy rain possible
32° /18° 2.3 mm 7
Sept. 2 Light rain
Light rain
32° /18° 1.1 mm 8
Sept. 3 Light rain
Light rain
30° /16° 3.5 mm 8
Sept. 4 Partly cloudy
Partly cloudy
32° /17° 0 mm 8
Sept. 5 Partly cloudy
Partly cloudy
34° /19° 0 mm 8
Sept. 6 Partly cloudy
Partly cloudy
35° /20° 0 mm 9
Sept. 7 Sunny
Sunny
36° /21° 0 mm 9
Sept. 8 Partly cloudy
Partly cloudy
36° /22° 0 mm 8
Sept. 9 Sunny
Sunny
37° /23° 0 mm 9
Sept. 10 Overcast
Overcast
34° /21° 0 mm 8
Sept. 11 Partly cloudy
Partly cloudy
31° /18° 0 mm 8
Sept. 12 Sunny
Sunny
29° /15° 0 mm 8
Sept. 13 Sunny
Sunny
27° /15° 0 mm 7
Sept. 14 Partly cloudy
Partly cloudy
28° /14° 0 mm 7
Sept. 15 Partly cloudy
Partly cloudy
28° /16° 0 mm 7
Sept. 16 Partly cloudy
Partly cloudy
25° /13° 0.1 mm 7
Sept. 17 Partly cloudy
Partly cloudy
24° /13° 0 mm 6
Sept. 18 Cloudy
Cloudy
23° /12° 0 mm 6
Sept. 19 Partly cloudy
Partly cloudy
22° /12° 0 mm 6
Sept. 20 Partly cloudy
Partly cloudy
22° /11° 0 mm 6
Sept. 21 Patchy rain possible
Patchy rain possible
22° /11° 0.1 mm 6
Sept. 22 Overcast
Overcast
28° /13° 0 mm 7
Sept. 23 Partly cloudy
Partly cloudy
31° /18° 0 mm 8
Sept. 24 Partly cloudy
Partly cloudy
31° /18° 0 mm 8
Sept. 25 Sunny
Sunny
30° /16° 0 mm 8
Sept. 26 Overcast
Overcast
31° /15° 0 mm 7
Sept. 27 Partly cloudy
Partly cloudy
32° /16° 0 mm 8
Sept. 28 Sunny
Sunny
30° /17° 0 mm 8
Sept. 29 Sunny
Sunny
30° /16° 0 mm 8
Sept. 30 Light rain shower
Light rain shower
27° /15° 1.7 mm 7
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.

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 28° and lows near 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Ontario during September?
Expect minimal rainfall in Ontario during September, with a total of 17.4 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 15 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 ☀️

Quick links

Location coordinates Where is Ontario?

Get accurate weather forecasts for Ontario, located at latitude 34.063 and longitude -117.651. Stay updated with localized weather information tailored for Ontario.

Related locations
Select a location for accurate weather forecast
More Locations
Found a mistake?
We appreciate your attention to details. Tell us here.