Which lakes in Ireland are best to swim in?

8 of 10 designated bathing waters in Ireland are rated Excellent for 2025 under the EU Bathing Water Directive. That class measures E. coli and intestinal enterococci only — it is not a safety clearance.

Is it safe to swim in Ireland lakes?

The official class is a bacteriological rating, not a safety clearance. It does not cover algal blooms, nutrients, water clarity, currents, or depth. Conditions change after heavy rain. Check local signage and the operator's current notices before entering the water.

How is lake water quality measured in Ireland?

209 named lakes in Ireland have official phosphorus and chlorophyll-a from the Environmental Protection Agency of Ireland, via UNEP GEMS/Water, with WFD lake names from EPA Ireland, 2018–2023. These are the authority's own measurements, shown as reported.

Whose ratings do the Ireland lake pages show?

The publishing authority's own. Pages for lakes in Ireland show the values and classes that authority reports, with the season or year each was taken.

Lakes in Ireland, 10 Swim Sites + 209 Lakes

Excellent: 8Good: 2

Lake map

Map shows 219 lakes with coordinates · list below has 90

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Best-rated lakes to swim in Ireland

Officially classified Excellent for the 2025 bathing season, ranked by how often that class has held.

Ballyallia Lake, EnnisExcellent · Excellent 11/11 seasons
BallycuggeranExcellent · Excellent 11/11 seasons
Bathing Place At PortumnaExcellent · Excellent 11/11 seasons
Keeldra LoughExcellent · Excellent 11/11 seasons
Loughrea LakeExcellent · Excellent 11/11 seasons
Mountshannon, Lough DergExcellent · Excellent 11/11 seasons
Portnashangan, Lough OwelExcellent · Excellent 11/11 seasons
The Cut, Lough LeneExcellent · Excellent 11/11 seasons

Every rated bathing water in Ireland

Ballyallia Lake, EnnisExcellent · Excellent 11/11 seasons
BallycuggeranExcellent · Excellent 11/11 seasons
Bathing Place At PortumnaExcellent · Excellent 11/11 seasons
Keeldra LoughExcellent · Excellent 11/11 seasons
Loughrea LakeExcellent · Excellent 11/11 seasons
Mountshannon, Lough DergExcellent · Excellent 11/11 seasons
Portnashangan, Lough OwelExcellent · Excellent 11/11 seasons
The Cut, Lough LeneExcellent · Excellent 11/11 seasons
Lilliput, Lough EnnellGood · Excellent 0/9 seasons
Dromineer BeachGood · Excellent 0/1 seasons

Places in Ireland

Killarney lakesPlace · 3 lakes
Shannon lakesPlace · 9 lakes
Wicklow mountainsPlace · 7 lakes
DonegalCounty · 29 lakes
GalwayCounty · 28 lakes
MayoCounty · 20 lakes
ClareCounty · 19 lakes
CavanCounty · 16 lakes
KerryCounty · 16 lakes
MonaghanCounty · 14 lakes
LeitrimCounty · 12 lakes
CorkCounty · 11 lakes
RoscommonCounty · 9 lakes
WestmeathCounty · 8 lakes
SligoCounty · 7 lakes
WicklowCounty · 6 lakes
WaterfordCounty · 4 lakes
DublinCounty · 2 lakes
LimerickCounty · 2 lakes
LongfordCounty · 2 lakes
MeathCounty · 2 lakes
KildareCounty · 1 lakes
TipperaryCounty · 1 lakes

Named lakes

Lake	Place	Total phosphorus	Chlorophyll-a	Secchi	Year
Annaghmore Lough	Roscommon	11 µg/L	3.4 µg/L	—	2023
Golden Falls	Kildare	30 µg/L	—	—	2018
Lough Abisdealy	Cork	32 µg/L	12 µg/L	—	2022
Lough Acoose	Kerry	11 µg/L	4.4 µg/L	—	2023
Lough Acorrymore	Mayo	18 µg/L	1.5 µg/L	—	2022
Lough Acres	Leitrim	56 µg/L	23 µg/L	—	2022
Lough Acurry	Cavan	27 µg/L	2.3 µg/L	—	2022
Lough Aille	Mayo	19 µg/L	2.8 µg/L	—	2022
Lough Akibbon	Donegal	16 µg/L	3.2 µg/L	—	2022
Lough Alewnaghta	Clare	24 µg/L	6.6 µg/L	—	2023
Lough Allen	Leitrim	16 µg/L	3.4 µg/L	—	2022
Lough Allua	Cork	15 µg/L	6.1 µg/L	—	2023
Lough An Tseisigh	Donegal	12 µg/L	2.3 µg/L	—	2023
Lough Anaserd	Galway	20 µg/L	1.9 µg/L	—	2022
Lough Annagh	Cavan	28 µg/L	4.2 µg/L	—	2022
Lough Annagh-White	Westmeath	15 µg/L	2.1 µg/L	—	2023
Lough Anure	Donegal	13 µg/L	1.9 µg/L	—	2023
Lough Ardan	Cavan	32 µg/L	3.8 µg/L	—	2022
Lough Ardderry	Galway	12 µg/L	1.9 µg/L	—	2023
Lough Arrow	Sligo	13 µg/L	2.2 µg/L	—	2023
Lough Atedaun	Clare	34 µg/L	2.6 µg/L	—	2023
Lough Atrain	Cavan	50 µg/L	17 µg/L	—	2022
Lough Aughrusbeg	Galway	13 µg/L	3.6 µg/L	—	2023
Lough Avaghon	Monaghan	43 µg/L	9.8 µg/L	—	2022
Lough Ballaghkeeran	Westmeath	17 µg/L	10 µg/L	—	2022
Lough Ballin	Cork	43 µg/L	13 µg/L	—	2022
Lough Ballin	Mayo	38 µg/L	9.4 µg/L	—	2022
Lough Ballynahinch	Galway	17 µg/L	2.3 µg/L	—	2022
Lough Ballynakill	Galway	16 µg/L	2.3 µg/L	—	2022
Lough Ballyquirke	Galway	13 µg/L	2.1 µg/L	—	2022
Lough Ballyshunnock	Waterford	42 µg/L	19 µg/L	—	2022
Lough Bane Noggin Hill	Meath	12 µg/L	2.5 µg/L	—	2023
Lough Barra	Donegal	14 µg/L	1.7 µg/L	—	2023
Lough Bawn	Cavan	46 µg/L	1.6 µg/L	—	2022
Lough Bawn	Monaghan	27 µg/L	11 µg/L	—	2022
Lough Beaghcauneen	Galway	13 µg/L	2.5 µg/L	—	2022
Lough Belhavel	Leitrim	47 µg/L	14 µg/L	—	2022
Lough Belle	Waterford	25 µg/L	5.8 µg/L	—	2022
Lough Beltra	Mayo	14 µg/L	2.4 µg/L	—	2023
Lough Bleach	Limerick	14 µg/L	3.0 µg/L	—	2022
Lough Boderg	Roscommon	23 µg/L	4.9 µg/L	—	2022
Lough Bofin	Leitrim	28 µg/L	4.0 µg/L	—	2022
Lough Bofin	Galway	18 µg/L	1.3 µg/L	—	2022
Lough Bofinna	Cork	13 µg/L	6.8 µg/L	—	2022
Lough Brackan	Meath	24 µg/L	14 µg/L	—	2022
Lough Bray Lower	Wicklow	25 µg/L	3.1 µg/L	—	2022
Lough Bridget	Clare	21 µg/L	1.8 µg/L	—	2022
Lough Brin	Kerry	12 µg/L	4.9 µg/L	—	2023
Lough Bunny	Clare	13 µg/L	1.5 µg/L	—	2023
Lough Cam	Kerry	15 µg/L	2.8 µg/L	—	2023
Lough Caragh	Kerry	12 µg/L	2.8 µg/L	—	2023
Lough Carra	Mayo	12 µg/L	2.2 µg/L	—	2023
Lough Carrigavantry	Waterford	22 µg/L	3.2 µg/L	—	2022
Lough Carrigdrohid	Cork	22 µg/L	6.8 µg/L	—	2022
Lough Carrowmore	Mayo	19 µg/L	4.4 µg/L	—	2023
Lough Castle	Clare	22 µg/L	3.6 µg/L	—	2022
Lough Castlebar	Mayo	17 µg/L	2.5 µg/L	—	2022
Lough Cavetown	Roscommon	25 µg/L	2.3 µg/L	—	2023
Lough Cloonaghlin	Kerry	—	4.3 µg/L	—	2022
Lough Conn	Mayo	15 µg/L	1.8 µg/L	—	2022
Lough Coolkellure	Cork	32 µg/L	6.9 µg/L	—	2022
Lough Coosan	Westmeath	11 µg/L	2.9 µg/L	—	2022
Lough Corconnelly	Monaghan	42 µg/L	25 µg/L	—	2022
Lough Corglass	Cavan	44 µg/L	3.5 µg/L	—	2023
Lough Corrib Lower	Galway	15 µg/L	1.9 µg/L	—	2023
Lough Corrib Upper	Galway	12 µg/L	1.8 µg/L	—	2023
Lough Cross	Mayo	46 µg/L	7.9 µg/L	—	2022
Lough Cullaun	Clare	12 µg/L	2.8 µg/L	—	2023
Lough Cullaunyheeda	Clare	18 µg/L	1.5 µg/L	—	2022
Lough Cullin	Mayo	14 µg/L	1.7 µg/L	—	2023
Lough Cummernamuck	Kerry	10 µg/L	2.6 µg/L	—	2022
Lough Curraghalicky	Cork	28 µg/L	14 µg/L	—	2022
Lough Currane	Kerry	10 µg/L	4.7 µg/L	—	2022
Lough Cutra	Galway	17 µg/L	1.5 µg/L	—	2022
Lough Dan	Wicklow	13 µg/L	2.2 µg/L	—	2023
Lough Derg	Tipperary	22 µg/L	2.9 µg/L	—	2023
Lough Derg	Donegal	13 µg/L	5.9 µg/L	—	2022
Lough Derg	Clare	17 µg/L	17 µg/L	—	2022
Lough Derravaragh	Westmeath	13 µg/L	3.2 µg/L	—	2022
Lough Derriana	Kerry	—	4.0 µg/L	—	2022

Showing 80 of 209 named lakes. Open a county or place page for the rest.

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Frequently asked questions

Which lakes in Ireland are best to swim in?: 8 of 10 designated bathing waters in Ireland are rated Excellent for 2025 under the EU Bathing Water Directive. That class measures E. coli and intestinal enterococci only — it is not a safety clearance.
Is it safe to swim in Ireland lakes?: The official class is a bacteriological rating, not a safety clearance. It does not cover algal blooms, nutrients, water clarity, currents, or depth. Conditions change after heavy rain. Check local signage and the operator's current notices before entering the water.
How is lake water quality measured in Ireland?: 209 named lakes in Ireland have official phosphorus and chlorophyll-a from the Environmental Protection Agency of Ireland, via UNEP GEMS/Water, with WFD lake names from EPA Ireland, 2018–2023. These are the authority's own measurements, shown as reported.
Whose ratings do the Ireland lake pages show?: The publishing authority's own. Pages for lakes in Ireland show the values and classes that authority reports, with the season or year each was taken.