Last updated: June 18, 2025
In Montreal-Ouest, Canada, the average temperature in September hovers around 17°C (62°F). Expect a minimum of 3°C (38°F) and a maximum reaching up to 31°C (88°F). With an average humidity of 78%, be prepared for some moisture, as you can expect approximately 69 mm (2.7 in) of precipitation spread over 9 days.
In September in Montreal-Ouest, the average temperature is 17°C (62°F). Maximum temperatures can reach 31°C (88°F), while minimums can drop to as low as 3°C (38°F). Travelers should be prepared for a range of weather conditions, making layered clothing a wise choice.
In Montreal-Ouest in September, the precipitation amount is 69 mm (2.7 in) spread over 9 days.
In Montreal-Ouest in September, humidity is 78%. With an average temperature of 17°C (62°F), this humidity feels like a warm, enveloping blanket, making travel feel a bit sticky and heavy but also refreshing, as long as you're prepared with light clothing and plenty of water.
In Montreal-Ouest in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Montreal-Ouest.
UV Risk Categories
Weather in Montreal-Ouest varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Montreal-Ouest, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -8°C (18°F) | 84 mm (3.3 inches) | 93% | low |
| February Weather | -7°C (20°F) | 85 mm (3.3 inches) | 92% | moderate |
| March Weather | -2°C (29°F) | 85 mm (3.3 inches) | 86% | moderate |
| April Weather | 6°C (42°F) | 120 mm (4.7 inches) | 85% | high |
| May Weather | 13°C (56°F) | 96 mm (3.8 inches) | 80% | very high |
| June Weather | 19°C (67°F) | 97 mm (3.8 inches) | 74% | very high |
| July Weather | 22°C (73°F) | 89 mm (3.5 inches) | 76% | very high |
| August Weather | 21°C (71°F) | 98 mm (3.9 inches) | 75% | very high |
| September Weather | 17°C (62°F) | 69 mm (2.7 inches) | 78% | high |
| October Weather | 10°C (51°F) | 132 mm (5.2 inches) | 86% | moderate |
| November Weather | 2°C (36°F) | 115 mm (4.5 inches) | 88% | moderate |
| December Weather | -4°C (24°F) | 89 mm (3.5 inches) | 89% | low |