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Sea temperature in Ireland

Live water temperatures and swimming conditions across 128 beaches on the Ireland coast.

Best time to swim in Ireland

The sea in Ireland peaks in August, when the water averages around 16°C.

On average, 0 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.

Outside peak season the water drops toward 9°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.

The coldest month is typically February at around 9°C, when cold-water swimmers dominate the coast.

Ireland sea temperature history

Long-term climatology for Ireland shows an annual mean sea temperature of 12°C, ranging from 9°C in winter to 16°C at the summer peak.

The seasonal swing is roughly 7°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.

Recent decades have trended slightly warmer at Ireland, in line with regional sea-surface temperature records for the wider basin.

Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.

Jan
10°C
Feb
9°C
Mar
9°C
Apr
10°C
May
11°C
Jun
13°C
Jul
15°C
Aug
16°C
Sep
15°C
Oct
14°C
Nov
12°C
Dec
11°C

Values are area averages; individual beaches vary by exposure and depth.

Ireland sea temperature: frequently asked questions

What is the warmest month to swim in Ireland?

August is the warmest month in Ireland, when the sea averages about 16°C. Late-season warmth often persists a few weeks after peak.

When is the sea coldest in Ireland?

The coldest month in Ireland is typically February, when the water averages around 9°C. Cold-water swimmers and surfers dominate this period.

When can you swim in Ireland without a wetsuit?

The sea in Ireland rarely climbs above 20°C, so a wetsuit is recommended year-round for anything longer than a quick dip.

Do I need a wetsuit in Ireland?

Outside peak summer the water in Ireland drops toward 9°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.

What is the average sea temperature in Ireland?

The long-term annual mean sea temperature in Ireland is about 12°C, based on multi-decadal climatology of the surrounding waters.

How do I check the current sea temperature in Ireland?

The live reading at the top of this page shows the current sea temperature in Ireland, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.

Ireland sea temperature by month

Average sea temperatures around Ireland for every month of the year, based on long-term Open-Meteo marine climatology.

Monthly average sea temperature in Ireland
MonthAverage sea
January10.0°C
February9.0°C
March9.0°C
April10.0°C
May11.0°C
June13.0°C
July15.0°C
August ⭐16.0°C
September15.0°C
October14.0°C
November12.0°C
December11.0°C

Monthly figures are modelled climatology averages, not live readings. How accurate is our data?

Coastal regions of Ireland

Region hubs with live sea temperatures, swim conditions and a beach directory.

West Coast
7 beaches
28 tracked beaches in West Coast, Ireland, with live Celtic Sea temperatures.

Warmest beaches in Ireland right now

BeachRegionSea
Portstewart StrandCounty Londonderry15.7°C
Duncannon BeachWexford15.7°C
Dog's BayWest Coast15.6°C
Pollan BayCounty Donegal15.6°C
Garryvoe BeachCounty Cork15.6°C
Booley BayCounty Wexford15.6°C
Garryvoe BeachCork15.6°C
Clonea BeachWaterford15.6°C
Killiney BeachDublin15.6°C
Marble Hill BeachDonegal15.6°C
Lettergesh BeachGalway15.6°C
Coral StrandGalway15.6°C
Doonbeg BeachClare15.6°C
InchydoneyWest Coast15.5°C
CurracloeEast Coast15.5°C
Silver StrandCounty Wicklow15.5°C
Whiterocks BeachCounty Antrim15.5°C
Marble Hill StrandCounty Donegal15.5°C
Mannin Bay BeachCounty Galway15.5°C
Fountainstown BeachCork15.5°C
Sandymount StrandDublin15.5°C
Skerries BeachDublin15.5°C
Enniscrone BeachSligo15.5°C
Rossnowlagh BeachDonegal15.5°C
Silver Strand Malin BegDonegal15.5°C
Aughrus BeachGalway15.5°C
Inch BeachWest Coast15.4°C
Cranfield BeachCounty Down15.4°C
Benone StrandCounty Londonderry15.4°C
Stroove BeachCounty Donegal15.4°C
Spiddal BeachCounty Galway15.4°C
Redbarn BeachCounty Cork15.4°C
Dunmore StrandCounty Waterford15.4°C
Garrettstown BeachCork15.4°C
Bray BeachWicklow15.4°C
Dollymount StrandDublin15.4°C
Blackrock BeachLouth15.4°C
Silver Strand SherkinMayo15.4°C
Gurteen BayGalway15.4°C
Kilkee BeachClare15.4°C
DerrynaneWest Coast15.3°C
Rossbeigh BeachKerry15.3°C
Fenit BeachKerry15.3°C
Coumeenoole BeachKerry15.3°C
Bunmahon BeachWaterford15.3°C
Dooagh BeachMayo15.3°C
Ross BeachMayo15.3°C
SandycoveCounty Dublin15.2°C
OwenahinchaCounty Cork15.2°C
Portnoo BeachDonegal15.2°C
Traught BeachGalway15.2°C
FanoreWest Coast15.1°C
Balbriggan Front StrandCounty Dublin15.1°C
Garretstown BeachCounty Cork15.1°C
Clonea BeachCounty Waterford15.1°C
Morriscastle BeachCounty Wexford15.1°C
Banna StrandKerry15.1°C
Ballybunion BeachKerry15.1°C
Redbarn BeachCork15.1°C
Clogherhead BeachLouth15.1°C
Mullaghmore BeachSligo15.1°C
Culdaff BeachDonegal15.1°C
Downings BeachDonegal15.1°C
Dogs BayGalway15.1°C
Ballinskelligs BeachCounty Kerry15.0°C
Ballymoney BeachCounty Wexford15.0°C
Barleycove BeachCork15.0°C
Ardmore BeachWaterford15.0°C
Ballymoney BeachWexford15.0°C
Glassilaun BeachGalway15.0°C
StreedaghWest Coast14.9°C
Bettystown BeachCounty Meath14.9°C
Tyrella BeachCounty Down14.9°C
Lisfannon BeachCounty Donegal14.9°C
Tullagh BayCounty Donegal14.9°C
Dugort BeachCounty Mayo14.9°C
Counsellor's BeachCounty Waterford14.9°C
Ventry BeachKerry14.9°C
Templetown BeachLouth14.9°C
Carrowniskey BeachMayo14.9°C
BallycuggaranClare14.9°C
Carrickfin BeachCounty Donegal14.8°C
Bertra BeachCounty Mayo14.8°C
Banna StrandCounty Kerry14.8°C
Inch BeachCounty Kerry14.8°C
Tramore BeachWaterford14.8°C
Greystones BeachWicklow14.8°C
Rosses PointSligo14.8°C
Portsalon BeachDonegal14.8°C
Old Head LouisburghMayo14.8°C
Laytown BeachCounty Meath14.7°C
Portrush East StrandCounty Antrim14.7°C
White StrandCounty Clare14.7°C
White Strand CaherciveenCounty Kerry14.7°C
Claycastle BeachCounty Cork14.7°C
Wine StrandKerry14.7°C
Courtown BeachWexford14.7°C
Fintra BeachDonegal14.7°C
Kinnagoe BayDonegal14.7°C
Mulranny BeachMayo14.7°C
Lahinch BeachClare14.7°C
Keem BayWest Coast14.6°C
Brittas BayEast Coast14.6°C
PortmarnockEast Coast14.6°C
Portrush West StrandCounty Antrim14.6°C
Garrylucas BeachCounty Cork14.6°C
Ballycotton BeachCork14.6°C
Youghal BeachCork14.6°C
Donabate BeachCounty Dublin14.5°C
Templetown BeachCounty Louth14.5°C
Ballycastle BeachCounty Antrim14.5°C
Owenahincha BeachCork14.5°C
Strandhill BeachSligo14.5°C
Streedagh BeachSligo14.5°C
Salthill BeachGalway14.5°C
Trá an DóilínGalway14.5°C
SeapointCounty Dublin14.4°C
Forty FootCounty Dublin14.4°C
Murlough BeachCounty Down14.4°C
Buncrana BeachCounty Donegal14.4°C
SilverstrandCounty Galway14.4°C
Maharees BeachCounty Kerry14.4°C
Rosslare BeachWexford14.4°C
Portrane BeachDublin14.4°C
Keel BeachMayo14.4°C
Spanish PointClare14.4°C
Malahide BeachDublin14.3°C
Bundoran BeachDonegal14.3°C

Sea temperature in Ireland — FAQ

How warm is the sea in Ireland in September?

The sea off Ireland averages about 15.0°C in September, based on long-term monthly averages for this coast.

When is the best time to swim in Ireland?

Ireland is warmest in August (around 16.0°C) and coldest in February (around 9.0°C). There are typically 0 months a year when the water sits above 22°C.

What is the average yearly sea temperature in Ireland?

Across all twelve months, the sea in Ireland averages about 12.1°C.

Do you need a wetsuit to swim in Ireland?

The sea in Ireland stays below 22°C even at its warmest (~16.0°C in August), so a 3/2mm or thicker wetsuit is recommended for longer swims year-round.