Can you swim at Portmarnock in January? — 10.0°C water
Cold — wetsuit recommended
Average sea · January
10.0°C
Live water now
…
Recommended wetsuit
5/4mm fullsuit + boots & gloves
cool
Cold. 10.0°C in January is cold-water swimming territory — a 4/3 mm full wetsuit, neoprene cap and short, repeated sessions are the safe approach.
Monthly averages set expectations, but the specific beach today depends on wind, swell and recent weather. Check the live value at the top of this page or open the Portmarnock live page for full conditions.
Frequently asked questions
What is the average sea temperature at Portmarnock in January?
Portmarnock averages 10.0°C in January, based on long-run climatology for the Irish Sea.
Is the sea warm enough to swim at Portmarnock in January?
Not without thermal protection — a wetsuit is recommended at 10.0°C.
Do I need a wetsuit at Portmarnock in January?
A 4/3 mm full wetsuit, boots and neoprene cap are recommended.
