September in Granby averages a daily high of 20.6°C with nights around 10.8°C. Expect roughly 11.7 wet days totalling 113mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Granby is May–September.
Based on GRANBY, QC CA (2.2km), 1995–2024. 24 years of September data.