Swimming in Northern Ireland in may 2025 Sea temperature by city in may
Do you want to go to the beach in Northern Ireland in may 2025? Is it the right month to go for pleasant temperatures and staying in the water for a long time? The answer is on this page with the sea temperatures in may in Northern Ireland by city and our opinion on the chances of enjoying pleasant sea conditions.
Sea temperature in Northern Ireland in may 2025
Here, find the average sea temperature in Northern Ireland in may in several coastal cities.
County Antrim in may
51°F
min: 49°F / max: 52°F
Ballycastle (Causeway Coast)
51°F
min: 49°F / max: 52°F
Larne
51°F
min: 49°F / max: 52°F
Carrickfergus
50°F
min: 49°F / max: 52°F
Glenariff
51°F
min: 49°F / max: 52°F
Newtownabbey
50°F
min: 49°F / max: 52°F
County Londonderry in may
52°F
min: 50°F / max: 53°F
Castlerock
51°F
min: 49°F / max: 53°F
Limavady
51°F
min: 50°F / max: 53°F
51°F
min: 49°F / max: 52°F
County Down in may
Donwpatrick
51°F
min: 49°F / max: 52°F
Annalong
51°F
min: 49°F / max: 52°F
Ballywalter
50°F
min: 48°F / max: 52°F
Bangor
50°F
min: 49°F / max: 52°F
Donaghadee
51°F
min: 49°F / max: 52°F
Dundrum
50°F
min: 49°F / max: 52°F
Where should you go swimming in Northern Ireland in the month of may?
Swimming in Northern Ireland in may is freezing
In may in Northern Ireland swimming conditions are generally the same everywhere.
Forget about swimming in Belfast, Ballycastle (Causeway Coast), Derry (Londonderry), Donwpatrick, Larne, Annalong, Ballywalter, Bangor, Carrickfergus, Castlerock, Donaghadee, Dundrum, Glenariff, Holywood, Kilkeel, Limavady, Millisle, Newcastle, Newtownabbey, Newtownards, Portrush, Portstewart and Warrenpoint in may! The water temperature is freezing, reaching as low as 49°F (and only 52°F at the best of times). Our advice: plan on sightseeing, and don't bring your beach towel!
Where to go swimming in Northern Ireland in may: the map of sea temperatures
ideal swimming 
pleasant swimming 
cool swimming 
cold swimming 
freezing swimmingWater temperature and seasonal norms in may
Belfast
| May | |||
| Average sea temperature | 51°F | ||
| Minimum sea temperature | 49°F | ||
| Maximum sea temperature | 52°F | ||
| Average outside temperature | 54°F | ||
| Maximum outside temperature | 58°F | ||
| Minimum outside temperature | 49°F | ||
| Precipitation | 3.8in | ||
| Number of days of precipitation | 7 jour(s) (21%) | ||
| Cloud cover | 56% | ||
| Our opinion | freezing swimming |
More information on swimming in Belfast in may
Ballycastle (Causeway Coast)
| May | |||
| Average sea temperature | 51°F | ||
| Minimum sea temperature | 49°F | ||
| Maximum sea temperature | 52°F | ||
| Average outside temperature | 52°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 49°F | ||
| Precipitation | 4.6in | ||
| Number of days of precipitation | 8 jour(s) (27%) | ||
| Cloud cover | 53% | ||
| Our opinion | freezing swimming |
Derry (Londonderry)
| May | |||
| Average sea temperature | 52°F | ||
| Minimum sea temperature | 50°F | ||
| Maximum sea temperature | 53°F | ||
| Average outside temperature | 52°F | ||
| Maximum outside temperature | 58°F | ||
| Minimum outside temperature | 47°F | ||
| Precipitation | 2.2in | ||
| Number of days of precipitation | 3 jour(s) (9%) | ||
| Cloud cover | 62% | ||
| Our opinion | freezing swimming |
More information on swimming in Derry (Londonderry) in may
Donwpatrick
| May | |||
| Average sea temperature | 51°F | ||
| Minimum sea temperature | 49°F | ||
| Maximum sea temperature | 52°F | ||
| Average outside temperature | 52°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 50°F | ||
| Precipitation | 2.4in | ||
| Number of days of precipitation | 4 jour(s) (12%) | ||
| Cloud cover | 50% | ||
| Our opinion | freezing swimming |
Larne
| May | |||
| Average sea temperature | 51°F | ||
| Minimum sea temperature | 49°F | ||
| Maximum sea temperature | 52°F | ||
| Average outside temperature | 52°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 49°F | ||
| Precipitation | 3.9in | ||
| Number of days of precipitation | 7 jour(s) (21%) | ||
| Cloud cover | 53% | ||
| Our opinion | freezing swimming |
List of coastal cities in Northern Ireland
| Belfast in may | freezing swimming |
| Ballycastle (Causeway Coast) in may | freezing swimming |
| Derry (Londonderry) in may | freezing swimming |
| Donwpatrick in may | freezing swimming |
| Larne in may | freezing swimming |
| Annalong in may | freezing swimming |
| Ballywalter in may | freezing swimming |
| Bangor in may | freezing swimming |
| Carrickfergus in may | freezing swimming |
| Castlerock in may | freezing swimming |
| Donaghadee in may | freezing swimming |
| Dundrum in may | freezing swimming |
| Glenariff in may | freezing swimming |
| Holywood in may | freezing swimming |
| Kilkeel in may | freezing swimming |
| Limavady in may | freezing swimming |
| Millisle in may | freezing swimming |
| Newcastle in may | freezing swimming |
| Newtownabbey in may | freezing swimming |
| Newtownards in may | freezing swimming |
| Portrush in may | freezing swimming |
| Portstewart in may | freezing swimming |
| Warrenpoint in may | freezing swimming |