September weather forecastMontreal, Canada
September
Weather in September
September marks the transition from summer to autumn, with temperature dipping to a comfortable high average of 20.8°C (69.4°F). Montreal in September is different from August, with cooler temperatures and less rainfall from 78mm (3.07") to 55mm (2.17"). As fall begins to set in, leaves start changing colors, uncovering a delightful palette of warm tones. The city ushers in the season change with harvest festivals and outdoor concerts. Despite the minor drop in temperature, the city continues to bustle with outdoor activities, balancing the final warm days with the emerging fall chill.Temperature
September marks a gentle change in average high-temperature, declining from August's warm 24.8°C (76.6°F) to an agreeable 20.8°C (69.4°F). During September, Montreal's temperature averages to a fresh 11.5°C (52.7°F) at night.Humidity
In Montreal, the average relative humidity in September is 76%.Rainfall
September is the month with the least rainfall. Rain falls for 12 days and accumulates 55mm (2.17") of precipitation.Snowfall
In Montreal, snow does not fall in June through September.Daylight
In September, the average length of the day in Montreal is 12h and 31min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:31 pm. On the last day of September, in Montreal, sunrise is at 6:52 am and sunset at 6:35 pm EDT.
Sunshine
The average sunshine in September is 8.5h.UV index
The average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for average individuals.Note: A daily maximum UV index of 3 in September translates into the following instructions:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Montreal, Canada
- Average high temperature in September: 20.8°C
The warmest month (with the highest average high temperature) is July (25.8°C).
The month with the lowest average high temperature is January (-5.8°C).
- Average low temperature in September: 11.5°C
The month with the highest average low temperature is July (16.3°C).
The coldest month (with the lowest average low temperature) is January (-13.1°C).
Average pressure in September
Montreal, Canada
- Average pressure in September: 1017.1mbar
The month with the highest atmospheric pressure is November (1017.8mbar).
The month with the lowest atmospheric pressure is June (1012.4mbar).
Average wind speed in September
Montreal, Canada
- Average wind speed in September: 11.1km/h
The windiest month (with the highest average wind speed) is April (14.3km/h).
The calmest month (with the lowest average wind speed) is August (10.9km/h).
Average humidity in September
Montreal, Canada
- Average humidity in September: 76%
The months with the highest relative humidity are January and February (90%).
The month with the lowest relative humidity is May (73%).
Average rainfall in September
Montreal, Canada
- Average rainfall in September: 55mm
The wettest month (with the highest rainfall) is May (85mm).
The driest month (with the least rainfall) is September (55mm).
Average rainfall days in September
Montreal, Canada
- Average rainfall days in September: 12 days
The months with the highest number of rainy days are May and July (17.8 days).
The month with the least rainy days is January (5 days).
Average snowfall in September
Montreal, Canada
- Average snowfall in September: 0mm
The month with the highest snowfall is January (293mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
Montreal, Canada
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (18.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Montreal, Canada
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 2h and 42min).
Average sunshine days in September
Montreal, Canada
- Average sunshine days in September: 16.2 days
The month with the most sunshine days is September (16.2 days).
The month with the least sunshine days is February (8.9 days).
Average UV index in September
Montreal, Canada
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February and December (UV index 1).
Average cloud cover in September
Montreal, Canada
- Average cloud cover in September: 38
The month with the most cloud cover is February (Cloud cover 71).
The month with the least cloud cover is July (Cloud cover 34).
Average visibility in September
Montreal, Canada
- Average visibility in September: 9km
The months with the highest visibility are April, May, June, July, August, September, October and November (9km).
The months with the lowest visibility are January and February (7km).
