Click on a day for an hourly weather forecast
The temperatures in Rennes in September are comfortable with low of 11°C and and high up to 22°C.
You can expect about 3 to 8 days of rain in Rennes during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Rennes in September 2025.
If you’re planning to visit Rennes in the near future, we highly recommend that you review the 14 day weather forecast for Rennes before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 8° / 3° | 6 | 24 | 2 | 59 mm | Bad | Rennes in January |
| February | 9° / 3° | 6 | 20 | 2 | 54 mm | Bad | Rennes in February |
| March | 12° / 4° | 4 | 26 | 1 | 48 mm | Ok | Rennes in March |
| April | 15° / 5° | 5 | 25 | 1 | 58 mm | Good | Rennes in April |
| May | 18° / 8° | 5 | 26 | 0 | 71 mm | Good | Rennes in May |
| June | 21° / 11° | 6 | 24 | 0 | 87 mm | Good | Rennes in June |
| July | 23° / 13° | 4 | 27 | 0 | 54 mm | Perfect | Rennes in July |
| August | 23° / 13° | 4 | 27 | 0 | 57 mm | Perfect | Rennes in August |
| September | 22° / 11° | 3 | 27 | 0 | 36 mm | Good | Rennes in September |
| October | 17° / 9° | 4 | 27 | 0 | 60 mm | Good | Rennes in October |
| November | 12° / 6° | 5 | 25 | 0 | 68 mm | Ok | Rennes in November |
| December | 9° / 4° | 6 | 24 | 1 | 72 mm | Ok | Rennes in December |