Portmarnock, Co. Dublin — Swimming, Tides, Access & Sea Temperature Guide | Wild Beauty
Portmarnock
Portmarnock — blue flag surf strand on Dublin Bay.
About Portmarnock
Portmarnock's Velvet Strand is a long, luxuriant ribbon of pale sand on the north Dublin coast, backed by dunes and looking out to Ireland's Eye and Lambay Island. Its smoothness earned it the 'Velvet Strand' name, and its openness made it a stage for early aviation history — pioneering long-distance flights set off from these firm sands in the 1930s.
Today it's a Blue Flag beach loved for swimming, walking and, when the wind's up, kite- and wind-surfing.
Swimming & safety
Portmarnock is a Blue Flag beach for 2026 — certified water quality, good facilities and lifeguard cover through the bathing season. Lifeguards patrol through the summer (Fingal / Dún Laoghaire–Rathdown / Dublin City councils): weekends in June, then daily in July and August. Swim within the flagged area when they're on duty, and mind the tide and any offshore wind.
Tides & conditions
The beach changes through the day with the tide, and swimming can shift from easy to lively as the wind and swell get up. Check the live tide, wind and sea-temperature page for Portmarnock before you travel — you can scrub forward to any date to plan a swim.
Getting there & facilities
There's a dedicated car park and further parking along the coast road, though it fills fast on fine days — arrive early. Toilets and a beachside café are close to hand, and it's reachable by bus or by DART to Portmarnock. The exposed strand catches the wind, which is a boon for kite-surfers and a reason to check conditions before swimming.
Nearby
From Portmarnock, Ireland's Eye and Howth Head, Malahide Castle and the fishing village of Howth are all nearby.
Reviews
See what other swimmers and visitors say — read reviews of Portmarnock on Google Maps →
Frequently asked questions
When is the best time to swim at Portmarnock?
Around high water on most Dublin bay beaches, since the tide retreats a long way. Check the live tide, wind and sea-temperature page for Portmarnock and pick a calm window.
Is Portmarnock lifeguarded?
Yes — Portmarnock has lifeguards through the summer season.
How do I get to Portmarnock by public transport?
Most Dublin bay swims are reachable by DART or rail — see the access notes above for the nearest station.
What is the sea temperature at Portmarnock today?
The current sea temperature and its 24-hour trend are shown live on the conditions page for Portmarnock.