August in Rennes averages a daily high of 24.8°C with nights around 13.8°C. Expect roughly 9.4 wet days totalling 44.8mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Rennes is May–September.
Based on RENNES ST JACQUES, FR (6.4km), 1995–2024. 30 years of August data.