September in Brest averages a daily high of 19°C with nights around 8.6°C. Expect roughly 9.4 wet days totalling 47.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Brest is May–September.
Based on BREST, BO (2.5km), 1995–2024. 18 years of September data.