Click on a day for an hourly weather forecast
The temperatures in Brittany 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 Brittany 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 Brittany in September 2025.
If you’re planning to visit Brittany in the near future, we highly recommend that you review the 14 day weather forecast for Brittany before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 8° / 3° | 6 | 24 | 2 | 59 mm | Bad | Brittany in January |
| February | 9° / 3° | 6 | 20 | 2 | 54 mm | Bad | Brittany in February |
| March | 12° / 4° | 4 | 26 | 1 | 48 mm | Ok | Brittany in March |
| April | 15° / 5° | 5 | 25 | 1 | 58 mm | Good | Brittany in April |
| May | 18° / 8° | 5 | 26 | 0 | 71 mm | Good | Brittany in May |
| June | 21° / 11° | 6 | 24 | 0 | 87 mm | Good | Brittany in June |
| July | 23° / 13° | 4 | 27 | 0 | 54 mm | Perfect | Brittany in July |
| August | 23° / 13° | 4 | 27 | 0 | 57 mm | Perfect | Brittany in August |
| September | 22° / 11° | 3 | 27 | 0 | 36 mm | Good | Brittany in September |
| October | 17° / 9° | 4 | 27 | 0 | 60 mm | Good | Brittany in October |
| November | 12° / 6° | 5 | 25 | 0 | 68 mm | Ok | Brittany in November |
| December | 9° / 4° | 6 | 24 | 1 | 72 mm | Ok | Brittany in December |