Click on a day for an hourly weather forecast
The temperatures in Brecon in September are quite cold with temperatures between 9°C and 16°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Brecon 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 Brecon in September 2025.
If you’re planning to visit Brecon in the near future, we highly recommend that you review the 14 day weather forecast for Brecon before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 5° / 1° | 10 | 13 | 8 | 144 mm | Awful | Brecon in January |
| February | 6° / 2° | 9 | 12 | 8 | 123 mm | Awful | Brecon in February |
| March | 8° / 2° | 8 | 18 | 5 | 88 mm | Awful | Brecon in March |
| April | 11° / 4° | 6 | 23 | 1 | 73 mm | Ok | Brecon in April |
| May | 14° / 6° | 8 | 23 | 0 | 103 mm | Ok | Brecon in May |
| June | 16° / 9° | 7 | 23 | 0 | 118 mm | Ok | Brecon in June |
| July | 18° / 11° | 7 | 24 | 0 | 110 mm | Ok | Brecon in July |
| August | 18° / 11° | 7 | 24 | 0 | 109 mm | Ok | Brecon in August |
| September | 16° / 9° | 6 | 24 | 0 | 89 mm | Good | Brecon in September |
| October | 12° / 7° | 9 | 22 | 0 | 137 mm | Bad | Brecon in October |
| November | 9° / 4° | 10 | 18 | 2 | 143 mm | Awful | Brecon in November |
| December | 6° / 3° | 11 | 15 | 5 | 156 mm | Awful | Brecon in December |