Click on a day for an hourly weather forecast
The temperatures in Barmouth in September are quite cold with temperatures between 9°C and 15°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Barmouth 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 Barmouth in September 2025.
If you’re planning to visit Barmouth in the near future, we highly recommend that you review the 14 day weather forecast for Barmouth before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 6° / 2° | 12 | 11 | 8 | 178 mm | Awful | Barmouth in January |
| February | 6° / 2° | 12 | 9 | 8 | 153 mm | Awful | Barmouth in February |
| March | 8° / 3° | 10 | 16 | 4 | 124 mm | Awful | Barmouth in March |
| April | 11° / 4° | 8 | 21 | 2 | 90 mm | Awful | Barmouth in April |
| May | 13° / 7° | 9 | 21 | 0 | 118 mm | Bad | Barmouth in May |
| June | 16° / 9° | 9 | 21 | 0 | 137 mm | Ok | Barmouth in June |
| July | 17° / 11° | 8 | 23 | 0 | 134 mm | Ok | Barmouth in July |
| August | 17° / 11° | 9 | 22 | 0 | 143 mm | Ok | Barmouth in August |
| September | 15° / 9° | 7 | 23 | 0 | 124 mm | Ok | Barmouth in September |
| October | 12° / 8° | 10 | 21 | 0 | 171 mm | Bad | Barmouth in October |
| November | 9° / 5° | 12 | 16 | 2 | 188 mm | Awful | Barmouth in November |
| December | 7° / 3° | 14 | 13 | 5 | 202 mm | Awful | Barmouth in December |