Portrush weather in September 2025

Q: How warm is it in Portrush in September?

Daytime temperatures usually reach 15°C in Portrush in September, falling to 9°C at night.

Q: How sunny is it in Portrush in September?

There are normally 3 hours of bright sunshine each day in Portrush in September - that's 26% of daylight hours.

Q: How warm is the sea around Portrush in September?

The average sea temperature around Portrush in September is 14°C.

Q: Does it rain in Portrush in September?

There are usually 20 days with some rain in Portrush in September and the average monthly rainfall is 107mm.

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

15
15°C max day temperature
3
3 hours of sunshine per day
20
20 days with some rainfall
9
9°C min night temperature
13
13 hours of daylight per day
0
No heat & humidity
107
107 mm of monthly rainfall
3
3 (Moderate) UV index
14
14°C sea temperature

More about Portrush

Portrush by month

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

Recommended for Northern Ireland

Rural Retreats: Group holiday cottages

Sale

Explore cottages in the UK for groups
Enjoy a range of facilities & activities
Filter search by selecting holiday preferences

Go to Rural Retreats deal >>

View all Rural Retreats offers

The September weather guide for Northern Ireland (Portrush) 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)