Toronto weather in September
In September, Toronto has an average high of 21 °C69 °F and an average low of 15 °C59 °F, with about 66 mm2.6 in of precipitation. It is the 3rd warmest month of the year and ranks 7th for precipitation.
How September compares with other months
Compared with August, September is 3.3 °C6 °F cooler on average and wetter by 7 mm0.3 in. Compared with October, September is 6.8 °C12.2 °F warmer on average and drier by 9 mm0.3 in. Daylight lasts about 12.4 hours around the middle of the month. Average relative humidity is 74% and the average cloud amount 60%.
Is September a good time to visit Toronto?
Yes — September is one of the most comfortable months to visit Toronto by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in September
For Toronto in September, pack light layers — T-shirts plus a light sweater or jacket.
September in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Toronto | 2169 | 1559 | 662.6 |
| Markham | 2374 | 1254 | 592.3 |
| Brampton | 2475 | 1253 | 692.7 |
| Ajax | 2373 | 1356 | 592.3 |
| Oshawa | 2373 | 1356 | 592.3 |
| St. Catharines | 2373 | 1559 | 813.2 |
| Guelph | 2373 | 1152 | 692.7 |
| Barrie | 2271 | 1254 | 512.0 |
| Brantford | 2474 | 1355 | 793.1 |
Nearby places that are more than 1 °C1.8 °F warmer in September: St. Catharines.
Other months in Toronto
- January−1 °C31 °F / −5 °C22 °F
- February−1 °C31 °F / −6 °C22 °F
- March3 °C38 °F / −3 °C27 °F
- April8 °C47 °F / 2 °C35 °F
- May14 °C58 °F / 7 °C45 °F
- June21 °C69 °F / 14 °C57 °F
- July25 °C76 °F / 18 °C64 °F
- August24 °C76 °F / 18 °C65 °F
- September21 °C69 °F / 15 °C59 °F
- October14 °C57 °F / 9 °C47 °F
- November7 °C45 °F / 3 °C37 °F
- December2 °C36 °F / −2 °C28 °F
Frequently asked questions
How warm is Toronto in September?
In September the average high in Toronto is 21 °C (69 °F) and the average low is 15 °C (59 °F).
Does it rain a lot in Toronto in September?
On average about 66 mm (2.6 in) of precipitation falls in September; it ranks 7th of the 12 months.
Is September the warmest month in Toronto?
No. The warmest month in Toronto is July, with an average high of 25 °C (76 °F). The coldest month is February, with an average low of -6 °C (22 °F).
How long is the day in Toronto in September?
In the middle of September the day in Toronto lasts about 12.4 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Toronto in September?
The average relative humidity in September is about 74%. This is a long-term average for the whole day.
How cloudy is Toronto in September?
On average about 60% of the sky is covered by cloud in September. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 99 m, while Toronto lies at about 161 m. Temperatures on this page were therefore adjusted by −0.4 °C0.7 °F using the standard lapse rate of 6.5 °C per 1,000 m.