Montreal Weather in September
Canada · Humid Continental climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Montreal sees average temperatures ranging from a low of 13.0°C (55.4°F) to a high of 21.3°C (70.3°F), with a mean of 16.9°C (62.4°F). Compared to the annual average of 8.1°C (46.6°F), this month is 8.8°C warmer than the yearly norm. Precipitation averages 79.8mm, making it approximately 15.0mm drier than the monthly average of 95.0mm. The city receives an average of 9.3 hours of sunshine per day during September, with relative humidity averaging 75.5%. Wind speeds reach an average maximum of 17.4 km/h. For travelers, this month offers a temperature experience in Montreal, with drier-than-average conditions compared to the rest of the year.
Montreal's climate offers four distinct seasons with dramatic temperature swings. I visited during the summer festival season and found the city alive with outdoor energy. The data shows that the best time to visit is May to September, when temperatures are warm and the city's famous festivals are in full swing. The winters are cold and snowy, but the city's underground city and indoor culture provide warm alternatives.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 20.9°C (69.6°F) | 16.9°C (62.4°F) | 10.9°C (51.6°F) |
| Rainfall | 153.6mm | 79.8mm | 102.5mm |
| Sunshine | 10.3 hrs | 9.3 hrs | 7.0 hrs |
| Humidity | 75.9% | 75.5% | 75.8% |
| Wind | 17.1 km/h | 17.4 km/h | 19.1 km/h |
| Rainy Days | 19.6 | 12.0 | 17.4 |
| Snowfall | 0.0 cm | 0.0 cm | 0.6 cm |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Montreal in September, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Montreal in September?
The average temperature in Montreal during September ranges from 13.0°C (55.4°F) to 21.3°C (70.3°F), with a mean of 16.9°C (62.4°F).
How much does it rain in Montreal in September?
Montreal receives an average of 79.8mm of precipitation in September, spread across approximately 12.0 rainy days.
What should I pack for Montreal in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is September a good time to visit Montreal?
September is a good time to visit Montreal, with comfortable temperatures and manageable rainfall.
Other Months for Montreal
Cities with Similar September Climate (Humid Continental)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 45.5°, -73.57°. Timezone: America/Montreal. Last updated: 2026-07-30.