Swansea in September
Planning a trip to Swansea in September? Here's the honest weather briefing for what spring looks like on the ground.
Expect the mercury to hit around 15.8 degrees during the day and settle at 7.2 degrees after dark. Manageable with a decent layer, and you'll warm up by midday.
September is 2.4 degrees cooler than Swansea's yearly average.
Rainfall in September averages 46mm over about 7 days. That means roughly a 23% chance of rain on any given day, decent odds for a dry day.
Solar exposure averages 13.3 MJ/m2 per day in September, with UV levels in the high range. Sun protection is still a good idea, especially around midday.
The Comfort Score is 4.1/10 for September. It's fine, but not the highlight of the calendar.
Packing tip: bring layers you can peel on and off, and serious sun protection.
Scroll down for the detailed climate data, or explore what nearby cities are like in September.
September at a Glance
Temperature Range
Daily temperature range in September. The bar shows the typical spread between overnight lows and afternoon highs.
What to Pack
- Layered clothing for mild to cool conditions
- A warm jumper or fleece for cool mornings and evenings
- A light rain jacket just in case
Coming From Overseas?
How September in Swansea stacks up against major cities around the world.
About 4 degrees cooler and considerably drier.
About 10 degrees cooler and considerably drier.
About 11 degrees cooler and considerably drier.
How September Compares
Swansea's monthly climate at a glance. September is highlighted.
| Month | Max | Min | Rain | Comfort |
|---|---|---|---|---|
| Jan | 22.7 | 13.3 | 62mm | 9.5 |
| Feb | 24.6 | 13.0 | 22mm | 10.0 |
| Mar | 22.6 | 11.9 | 24mm | 9.4 |
| Apr | 18.2 | 8.8 | 67mm | 5.6 |
| May | 15.1 | 7.6 | 59mm | 2.7 |
| Jun | 12.3 | 6.5 | 40mm | 1.0 |
| Jul | 12.3 | 5.3 | 92mm | 1.0 |
| Aug | 15.1 | 7.6 | 64mm | 2.9 |
| Sep | 15.8 | 7.2 | 46mm | 4.1 |
| Oct | 17.9 | 8.0 | 54mm | 6.0 |
| Nov | 19.8 | 10.6 | 77mm | 7.3 |
| Dec | 21.9 | 12.5 | 95mm | 8.8 |