Weather in Swansea for September 2025
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Until now, September 2025 in Swansea is slightly cooler than the historical average by -1.2 °C.
Expect cooler weather in the next days in Swansea with the forecast suggesting a temperature of 15.6 °C, lower than the historical average.
In general, the average temperature in Swansea at the beginning of September is 18.9 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 14.9 °C by the end of September.
Swansea experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 133.1 mm.
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Swansea Weather September
Temperatures trend during September in Swansea
September weather in Swansea day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Light rain shower | 18° /14° | 5.7 mm | 4 | |
| 2 Sept. | Light rain shower | 18° /13° | 2.3 mm | 4 | |
| 3 Sept. |  Partly cloudy | 18° /14° | 8 mm | 5 | |
| 4 Sept. |  Sunny | 18° /13° | 3 mm | 4 | |
| 5 Sept. | Sunny | 19° /13° | 6.6 mm | 5 | |
| 6 Sept. | Partly cloudy | 20° /15° | 2.6 mm | 5 | |
| 7 Sept. | Light rain shower | 21° /15° | 4.4 mm | 4 | |
| 8 Sept. | Partly cloudy | 18° /15° | 4.1 mm | 5 | |
| 9 Sept. | Patchy rain possible | 18° /14° | 1.4 mm | 4 | |
| 10 Sept. | Light rain shower | 17° /13° | 2.8 mm | 4 | |
| 11 Sept. | Light rain shower | 16° /12° | 4.6 mm | 4 | |
| 12 Sept. |  Cloudy | 15° /11° | 5 mm | 4 | |
| 13 Sept. | Partly cloudy | 15° /10° | 4.2 mm | 4 | |
| 14 Sept. |  Overcast | 16° /12° | 8.1 mm | 4 | |
| 15 Sept. |  Moderate rain | 15° /13° | 6.5 mm | 0.7 | |
| 16 Sept. | Patchy rain possible | 15° /12° | 2.6 mm | 0.9 | |
| 17 Sept. | Moderate rain | 17° /13° | 16.4 mm | 0.1 | |
| 18 Sept. | Patchy rain possible | 19° /16° | 0.5 mm | 0.5 | |
| 19 Sept. | Patchy rain possible | 18° /16° | 0.8 mm | 0.2 | |
| 20 Sept. | Patchy rain possible | 18° /14° | 0.5 mm | 4 | |
| 21 Sept. | Patchy rain possible | 13° /12° | 3.5 mm | 3 | |
| 22 Sept. | Patchy rain possible | 15° /10° | 1.3 mm | 3 | |
| 23 Sept. | Patchy rain possible | 15° /10° | 0.3 mm | 3 | |
| 24 Sept. | Patchy rain possible | 14° /10° | 0.3 mm | 3 | |
| 25 Sept. | Patchy rain possible | 15° /8° | 0 mm | 3 | |
| 26 Sept. | Partly cloudy | 14° /10° | 0.1 mm | 4 | |
| 27 Sept. | Sunny | 15° /8° | 0 mm | 4 | |
| 28 Sept. | Sunny | 16° /9° | 0 mm | 4 | |
| 29 Sept. | Partly cloudy | 14° /11° | 9 mm | 4 | |
| 30 Sept. | Patchy rain possible | 16° /11° | 3.6 mm | 4 | |
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Swansea in September - FAQ
September rainfall patterns in Swansea
UV exposure in Swansea during September
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Where is Swansea?Get accurate weather forecasts for Swansea, located at latitude 51.621 and longitude -3.943. Stay updated with localized weather information tailored for Swansea.