Click on a day for an hourly weather forecast
The temperatures in Swansea in September are quite cold with temperatures between 7°C and 14°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Swansea 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 Swansea in September 2025.
If you’re planning to visit Swansea in the near future, we highly recommend that you review the 14 day weather forecast for Swansea before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 21° / 13° | 3 | 28 | 0 | 78 mm | Good | Swansea in January |
| February | 20° / 13° | 4 | 25 | 0 | 77 mm | Good | Swansea in February |
| March | 19° / 13° | 4 | 27 | 0 | 99 mm | Good | Swansea in March |
| April | 17° / 11° | 2 | 28 | 0 | 46 mm | Good | Swansea in April |
| May | 15° / 9° | 3 | 28 | 0 | 60 mm | Good | Swansea in May |
| June | 13° / 7° | 4 | 26 | 0 | 79 mm | Ok | Swansea in June |
| July | 12° / 6° | 3 | 28 | 0 | 52 mm | Ok | Swansea in July |
| August | 13° / 6° | 4 | 27 | 0 | 83 mm | Ok | Swansea in August |
| September | 14° / 7° | 3 | 27 | 0 | 75 mm | Good | Swansea in September |
| October | 16° / 8° | 3 | 28 | 0 | 68 mm | Good | Swansea in October |
| November | 18° / 10° | 4 | 26 | 0 | 94 mm | Good | Swansea in November |
| December | 19° / 11° | 3 | 28 | 0 | 70 mm | Good | Swansea in December |