May in Rennes averages a daily high of 19.5°C with nights around 9.2°C. Expect roughly 11.6 wet days totalling 57.3mm. 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 May data.