Wales weather in September 2025

Expect 18°C daytime maximum temperatures in the shade with on average 5 hours of sunshine per day in Wales in September. Check more long-term weather averages for Wales in September before you book your next holiday to Wales in 2025/2026.

  • 18°C maximum daytime temperature in September in Wales (Cardiff)18
    18°C max day temperature
  • 5 hours of sunshine per day
  • 15 days with some rainfall in September in Wales (Cardiff)15
    15 days with some rainfall
  • 10°C minimum night-time temperature in September in Wales (Cardiff)10
    10°C min night temperature
  • 13 hours of daylight per day in September in Wales (Cardiff)13
    13 hours of daylight per day
  • No heat & humidity in September in Wales (Cardiff)0
    No heat & humidity
  • 91 mm monthly rainfall in September in Wales (Cardiff)91
    91 mm of monthly rainfall
  • UV (maximum) index 4 (Moderate) in September in Wales (Cardiff)4
    4 (Moderate) UV index
  • 17°C sea temperature in September in Wales (Cardiff)17
    17°C sea temperature

More about Wales

Wales by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for Wales

  • Save EXTRA £50 on UK breaks with Luxury Cottages
  • No minimum stay. Book online with exclusive discount code
  • Offer cannot be combined with other promotions
Show discount codeShow discount code ******C50

Expires at 23:59 on Tuesday 31st Dec 2024 · View all Luxury Cottages offers

Luxury CottagesUK holiday finder

The September weather guide for Wales (Cardiff) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Top Wales destinations

Below are average maximum temperatures at popular countries, regions and places in Wales in September. Select a holiday destination to see more weather parameters.

All Wales regions

All Wales destinations

Metric (°C / mm)  |  Imperial (°F / inches)

Back to top

More about Wales

How hot is it in Wales in September?

Daytime temperatures usually reach 18°C in Cardiff, Wales in September, falling to 10°C at night.

How sunny is it in Wales in September?

There are normally 5 hours of bright sunshine each day in Cardiff, Wales in September - that's 37% of daylight hours.

How warm is the sea around Wales in September?

The average sea temperature around Cardiff, Wales in September is 17°C.

Does it rain in Wales in September?

There are usually 15 days with some rain in Cardiff, Wales in September and the average monthly rainfall is 91mm.

Wales September sunrise & sunset times

Browse the sunrise and sunset times for Wales in September 2025. Select a month to view Wales sunrise and sunset times for the next 12 months. The Wales sunrise and sunset times shown below are for Cardiff.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 05:26 18:59
Monday, 15th September 2025 05:48 18:27
Tuesday, 30th September 2025 06:12 17:52

Related posts

Popular travel offers

Explore holidays in the sun for less

More holidays

Airport parking

More parking

Airport lounges

More lounges

Top ^