Northen Ireland — Water Temperature Today and Throughout the Year
Discover water temperatures in Northen Ireland (United Kingdom), with real-time data and annual trends. Find all locations in the region and check the water temperature in them. We find every place where you can swim and show you the water temperature there today and throughout the year.
Sea Water Temperature Along the Coast
Chart of Average Temperature Changes Over the Last 60 Days
Places with the Warmest Sea Water Today
The Most Popular Seaside Places
- Portstewart47°F
- Kilkeel45°F
- Bangor48°F
- Strangford47°F
- Ballycastle47°F
- Portballintrae47°F
- Ballyhalbert48°F
- Rostrevor45°F
- Warrenpoint45°F
- Kilclief47°F
- Dunseverick47°F
- Annalong45°F
- Cushendall47°F
- Portavogie47°F
- Waterfoot47°F
- Cloughey45°F
- Donaghadee48°F
- Castlerock47°F
- Belfast46°F
- Portrush47°F
- Dundrum46°F
- Londonderry46°F
- Carrickfergus45°F
- Larne48°F
- Carnlough46°F
- Millisle45°F
- Ardglass45°F
- Ballywalter45°F
- Greyabbey48°F
- Glynn48°F
- Kircubbin47°F
- Whitehead46°F
Coastal Seas and Oceans
Water Temperature in Lakes and Rivers
Popular Lakes
Popular Rivers
Popular Places
Water Temperature and Swimming Overview
Regions and Map
Water Temperature Trends
The sea temperature along the coast of Northern Ireland is influenced by the North Atlantic Ocean, making it relatively cool throughout the year. In the summer months, from June to September, the water temperature typically ranges between 13–16°C (55–61°F), with the warmest conditions usually found in August. Coastal areas such as Bangor, Portrush, and Newcastle experience slightly milder temperatures due to their positioning along the Irish Sea, while the more exposed North Atlantic coast can remain on the lower end of this range. Even in the warmest months, the sea remains quite chilly compared to the southern parts of the UK.
During the winter, from December to March, the sea temperature drops significantly, averaging between 7–10°C (45–50°F). The coldest waters are typically found in February and early March, when temperatures can fall as low as 6°C (43°F). Due to the consistently cool water temperatures, sea swimming in Northern Ireland is often done with wetsuits outside of summer. However, the region's coastal beauty, with its rugged cliffs and scenic beaches, attracts cold-water swimmers year-round, especially those who enjoy the benefits of open-water swimming in colder conditions.