weather in montreal in september
Weather in Montreal in September. Montreal temperatures in September range from 10 to 22 and there is an average of 18 days of rain. Weather Facts - Montreal in September. * The warmest temperature recorded in in September is 34Â°C. * The coldest temperature recorded in Montreal in September is (-3Â°C) * The average rainfall in Montreal in September is 91 mm. Yearly Average for Montreal. Max Temp.