Coldest sea in Ireland

169 coastal locations in Ireland ranked by year-round average sea temperature, coldest first. The regional average is 12.3°C. The top of the list is where the water stays cold all year. The contrast list at the bottom shows the warmest coasts for context.

Coldest location

Moville

Year-round average 11.4°C in Ireland

Regional average

12.3°C

across all 169 Ireland coastal locations

Coldest month

February

9.0°C region-wide average

Ireland monthly average 9.0°C to 16.0°C

Warmest month August 16.0°C
Coldest month February 9.0°C
Annual mean 12.3°C
Months above 20°C 0 of 12

Month by month across Ireland

Sea temperatures in Ireland swing from 9.0°C in February to 16.0°C in August on average across every coast we track. That spread of 7°C hides much bigger swings at individual locations.

Want a specific month? Pick one for a dedicated ranking:

Ireland sea temperature map

Today's pin colours show the latest daily reading at every Ireland location we track. Cool blues cluster around the high-latitude coasts.

Zoom in to see individual locations. Click a pin for water temperatures. View list →

°C -2 0 1 3 5 7 9 11 13 15 17 19 21 24 27 30 35

Top 50 coldest locations in Ireland

Coastal locations across Ireland sorted by year-round average, coldest first. Honest cold-water swimming country. Click any place for its 30-day chart, monthly profile, and 10-year history.

#	Location	Country	Annual mean	Latest
1	Moville	Ireland	11.4°C	10.4°C
2	Inishtrahull County Donegal	Ireland	11.6°C	10.4°C
3	Buncrana	Ireland	11.6°C	10.7°C
4	Bulbinbeg County Donegal	Ireland	11.7°C	10.7°C
5	Drogheda	Ireland	11.7°C	12.1°C
6	Malin Head County Donegal	Ireland	11.7°C	10.7°C
7	Trawbreaga Bay County Donegal	Ireland	11.7°C	10.7°C
8	Blackrock County Louth	Ireland	11.8°C	—
9	Soldiers Point County Louth	Ireland	11.8°C	12.1°C
10	Balbriggan	Ireland	11.8°C	11.8°C
11	Bettystown	Ireland	11.8°C	11.8°C
12	Carlingford	Ireland	11.8°C	11.8°C
13	Dundalk	Ireland	11.8°C	11.8°C
14	Laytown	Ireland	11.8°C	11.8°C
15	Rush	Ireland	11.8°C	11.8°C
16	Skerries	Ireland	11.8°C	11.8°C
17	Cranford Bay County Donegal	Ireland	11.9°C	10.9°C
18	Fanad Head County Donegal	Ireland	11.9°C	10.9°C
19	Rathmullan County Donegal	Ireland	11.9°C	10.9°C
20	Dunany Point County Louth	Ireland	11.9°C	11.8°C
21	Greenore County Louth	Ireland	11.9°C	11.8°C
22	Blackrock	Ireland	11.9°C	11.8°C
23	Bray	Ireland	11.9°C	11.9°C
24	Clogherhead	Ireland	11.9°C	11.8°C
25	Dalkey	Ireland	11.9°C	11.8°C

Show 25 more ▸

26	Donabate	Ireland	11.9°C	11.8°C
27	Dublin	Ireland	11.9°C	11.9°C
28	Dun Laoghaire	Ireland	11.9°C	11.8°C
29	Forty Foot	Ireland	11.9°C	11.8°C
30	Greystones	Ireland	11.9°C	11.9°C
31	Howth	Ireland	11.9°C	11.8°C
32	Killiney	Ireland	11.9°C	11.8°C
33	Malahide	Ireland	11.9°C	11.8°C
34	Monkstown	Ireland	11.9°C	11.8°C
35	Portmarnock	Ireland	11.9°C	11.8°C
36	Portraine	Ireland	11.9°C	11.8°C
37	Sandycove	Ireland	11.9°C	11.8°C
38	Seapoint	Ireland	11.9°C	11.8°C
39	Donegal	Ireland	11.9°C	11.6°C
40	Killybegs	Ireland	11.9°C	11.6°C
41	Bundoran	Ireland	11.9°C	11.8°C
42	Dunfanaghy County Donegal	Ireland	11.9°C	11.0°C
43	Mullaghmore	Ireland	11.9°C	11.8°C
44	Mulroy Bay (Bar) County Donegal	Ireland	11.9°C	11.0°C
45	Sheep Haven County Donegal	Ireland	11.9°C	11.0°C
46	Sligo	Ireland	11.9°C	11.8°C
47	An Ros County Dublin	Ireland	12.0°C	11.8°C
48	River Boyne Entrance County Meath	Ireland	12.0°C	11.8°C
49	Howth Harbour County Dublin	Ireland	12.0°C	11.9°C
50	North Wall (Dublin) County Dublin	Ireland	12.0°C	11.9°C

Warmest 10 in Ireland for contrast

Same data flipped. Useful if you want to know which Ireland coasts stay warmest year-round before you commit to a cold-water swim trip.

#	Location	Country	Annual mean
1	Ardmore	Ireland	12.9°C
2	Ballycotton County Cork	Ireland	12.8°C
3	Youghal	Ireland	12.8°C
4	Castletownshend County Cork	Ireland	12.8°C
5	Garretstown Beach	Ireland	12.8°C
6	Kilbrittain	Ireland	12.8°C
7	Kinsale	Ireland	12.8°C
8	Garryvoe	Ireland	12.8°C
9	Baltimore County Cork	Ireland	12.8°C
10	Clonakilty	Ireland	12.8°C