Swimming in Northern Ireland in october 2025 Sea temperature by city in october
Do you want to go to the beach in Northern Ireland in october 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 october in Northern Ireland by city and our opinion on the chances of enjoying pleasant sea conditions.
Sea temperature in Northern Ireland in october 2025
Here, find the average sea temperature in Northern Ireland in october in several coastal cities.
County Antrim in october
56°F
min: 55°F / max: 58°F
Ballycastle (Causeway Coast)
56°F
min: 55°F / max: 58°F
Larne
56°F
min: 55°F / max: 58°F
Carrickfergus
56°F
min: 55°F / max: 58°F
Glenariff
56°F
min: 55°F / max: 58°F
Newtownabbey
57°F
min: 55°F / max: 58°F
County Londonderry in october
56°F
min: 54°F / max: 58°F
Castlerock
56°F
min: 55°F / max: 58°F
Limavady
56°F
min: 54°F / max: 58°F
56°F
min: 54°F / max: 58°F
County Down in october
Donwpatrick
58°F
min: 56°F / max: 59°F
Annalong
58°F
min: 56°F / max: 59°F
Ballywalter
57°F
min: 55°F / max: 58°F
Bangor
56°F
min: 55°F / max: 58°F
Donaghadee
57°F
min: 55°F / max: 58°F
Dundrum
58°F
min: 56°F / max: 59°F
Where should you go swimming in Northern Ireland in the month of october?
Swimming in Northern Ireland in october is freezing
In october 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 october! The water temperature is freezing, reaching as low as 55°F (and only 58°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 october: the map of sea temperatures
ideal swimming 
pleasant swimming 
cool swimming 
cold swimming 
freezing swimmingWater temperature and seasonal norms in october
Belfast
| October | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 55°F | ||
| Maximum sea temperature | 58°F | ||
| Average outside temperature | 52°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 49°F | ||
| Precipitation | 5.2in | ||
| Number of days of precipitation | 8 jour(s) (26%) | ||
| Cloud cover | 61% | ||
| Our opinion | freezing swimming |
More information on swimming in Belfast in october
Ballycastle (Causeway Coast)
| October | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 55°F | ||
| Maximum sea temperature | 58°F | ||
| Average outside temperature | 54°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 50°F | ||
| Precipitation | 6.5in | ||
| Number of days of precipitation | 11 jour(s) (34%) | ||
| Cloud cover | 61% | ||
| Our opinion | freezing swimming |
Derry (Londonderry)
| October | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 54°F | ||
| Maximum sea temperature | 58°F | ||
| Average outside temperature | 52°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 47°F | ||
| Precipitation | 2.4in | ||
| Number of days of precipitation | 3 jour(s) (11%) | ||
| Cloud cover | 66% | ||
| Our opinion | freezing swimming |
More information on swimming in Derry (Londonderry) in october
Donwpatrick
| October | |||
| Average sea temperature | 58°F | ||
| Minimum sea temperature | 56°F | ||
| Maximum sea temperature | 59°F | ||
| Average outside temperature | 56°F | ||
| Maximum outside temperature | 58°F | ||
| Minimum outside temperature | 54°F | ||
| Precipitation | 4.3in | ||
| Number of days of precipitation | 7 jour(s) (22%) | ||
| Cloud cover | 56% | ||
| Our opinion | freezing swimming |
Larne
| October | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 55°F | ||
| Maximum sea temperature | 58°F | ||
| Average outside temperature | 54°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 52°F | ||
| Precipitation | 5.3in | ||
| Number of days of precipitation | 8 jour(s) (26%) | ||
| Cloud cover | 60% | ||
| Our opinion | freezing swimming |
List of coastal cities in Northern Ireland
| Belfast in october | freezing swimming |
| Ballycastle (Causeway Coast) in october | freezing swimming |
| Derry (Londonderry) in october | freezing swimming |
| Donwpatrick in october | freezing swimming |
| Larne in october | freezing swimming |
| Annalong in october | freezing swimming |
| Ballywalter in october | freezing swimming |
| Bangor in october | freezing swimming |
| Carrickfergus in october | freezing swimming |
| Castlerock in october | freezing swimming |
| Donaghadee in october | freezing swimming |
| Dundrum in october | freezing swimming |
| Glenariff in october | freezing swimming |
| Holywood in october | freezing swimming |
| Kilkeel in october | freezing swimming |
| Limavady in october | freezing swimming |
| Millisle in october | freezing swimming |
| Newcastle in october | freezing swimming |
| Newtownabbey in october | freezing swimming |
| Newtownards in october | freezing swimming |
| Portrush in october | freezing swimming |
| Portstewart in october | freezing swimming |
| Warrenpoint in october | freezing swimming |