Donegal weather in September 2025

Expect 15°C daytime maximum temperatures in the shade with on average 3 hours of sunshine per day in Donegal in September. Check more long-term weather averages for Donegal in September before you book your next holiday to Ireland in 2025/2026.

  • 15°C maximum daytime temperature in September in Donegal15
    15°C max day temperature
  • 3 hours of sunshine per day
  • 22 days with some rainfall in September in Donegal22
    22 days with some rainfall
  • 8°C minimum night-time temperature in September in Donegal8
    8°C min night temperature
  • 13 hours of daylight per day in September in Donegal13
    13 hours of daylight per day
  • No heat & humidity in September in Donegal0
    No heat & humidity
  • 145 mm monthly rainfall in September in Donegal145
    145 mm of monthly rainfall
  • UV (maximum) index 3 (Moderate) in September in Donegal3
    3 (Moderate) UV index
  • 15°C sea temperature in September in Donegal15
    15°C sea temperature

More about Donegal

Donegal by month

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

Recommended for Ireland

Red Carnation Hotels: Top 5-star luxury hotel offers

  • Explore Red Carnation Hotels across Europe, Africa & Florida
  • Including London, Edinburgh, Ireland & Guernsey
  • Plus South Africa & Xigera Safari Lodge in Botswana
Go to Red Carnation Hotels deal >>

View all Red Carnation Hotels offers

The September weather guide for Ireland (Donegal) 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.

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

Back to top

More about Ireland

How warm is it in Donegal in September?

Daytime temperatures usually reach 15°C in Donegal in September, falling to 8°C at night.

How sunny is it in Donegal in September?

There are normally 3 hours of bright sunshine each day in Donegal in September - that's 27% of daylight hours.

How warm is the sea around Donegal in September?

The average sea temperature around Donegal in September is 15°C.

Does it rain in Donegal in September?

There are usually 22 days with some rain in Donegal in September and the average monthly rainfall is 145mm.

Donegal September sunrise & sunset times

Browse the sunrise and sunset times for Donegal in September 2025. Select a month to view Donegal sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 05:40 19:24
Monday, 15th September 2025 06:05 18:49
Tuesday, 30th September 2025 06:33 18:10

Related posts

Popular travel offers

Explore holidays in the sun for less

More holidays

Airport parking

More parking

Airport lounges

More lounges

Top ^