Northern Ireland weather in August 2025

Q: How hot is it in Northern Ireland in August?

Daytime temperatures usually reach 18°C in Belfast, Northern Ireland in August, falling to 11°C at night.

Q: How sunny is it in Northern Ireland in August?

There are normally 5 hours of bright sunshine each day in Belfast, Northern Ireland in August - that's 32% of daylight hours.

Q: How warm is the sea around Northern Ireland in August?

The average sea temperature around Belfast, Northern Ireland in August is 13°C.

Q: Does it rain in Northern Ireland in August?

There are usually 17 days with some rain in Belfast, Northern Ireland in August and the average monthly rainfall is 89mm.

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

18
18°C max day temperature
5
5 hours of sunshine per day
17
17 days with some rainfall
11
11°C min night temperature
15
15 hours of daylight per day
0
No heat & humidity
89
89 mm of monthly rainfall
5
5 (Moderate) UV index
13
13°C sea temperature

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The August weather guide for Northern Ireland (Belfast) 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 Northern Ireland destinations

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

18
Belfast
17
Londonderry

All Northern Ireland destinations

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

More about the UK

How hot is it in Northern Ireland in August?

Daytime temperatures usually reach 18°C in Belfast, Northern Ireland in August, falling to 11°C at night.

How sunny is it in Northern Ireland in August?

There are normally 5 hours of bright sunshine each day in Belfast, Northern Ireland in August - that's 32% of daylight hours.

How warm is the sea around Northern Ireland in August?

The average sea temperature around Belfast, Northern Ireland in August is 13°C.

Does it rain in Northern Ireland in August?

There are usually 17 days with some rain in Belfast, Northern Ireland in August and the average monthly rainfall is 89mm.

Northern Ireland August sunrise & sunset times

Browse the sunrise and sunset times for Northern Ireland in August 2025. Select a month to view Northern Ireland sunrise and sunset times for the next 12 months. The Northern Ireland sunrise and sunset times shown below are for Belfast.

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