September in Terrebonne averages a daily high of 21.3°C with nights around 10.9°C. Expect roughly 9 wet days totalling 92.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Terrebonne is May–September.
Based on RIVIERE DES PRAIRIES, QC CA (11.4km), 1995–2024. 27 years of September data.