Large coefficients indicate important high and low tides; major currents and movements usually take place on the sea bed. Sea temperature in Greystones in april: May May: 51°F (min: 49°F/max: 53°F) freezing swimming: Sea temperature in Greystones in may: June Jun. AVERAGE SEA TEMPERATURE in January for Greystones (Ireland) 10.0 o C. Temperature range in January: 8.2o C / 11.7o C. Current water temperature: 14.2o C Select language: DE | NL | PL RU | Switch to Fahrenheit. The warmest sea in Greystones in August is 16.1°C/61°F, and the coldest sea temperature in August is 13.8°C/56.8°F. Current temperature and sea water forecast in Ireland. Average February sea temperatures. But bear in mind that this tidal amplitude may be greatly affected by the weather and you should also consult the weather forecast in Greystones, the wind in Greystones and the surf forecast in Greystones before you go fishing. These figures are calculated from several years of recorded data and are the maximum, minimum and average temperatures of all the recorded years. AVERAGE SEA TEMPERATURE in April for Greystones (Ireland) 8.3 o C. Temperature range in April: 6.5o C / 10.1o C. Current water temperature: 11.7o C Average water temperature in Greystones in September is 14.7°C/58.5°F and therefore is not suitable for comfortable swimming. Coastal sea temperatures around Ireland Ocean temperature and marine climate data is provided daily by the National Oceanic and Atmospheric Administration 55°F (min: 52°F/max: 58°F) freezing swimming: Sea temperature in Greystones in june: July Jul. January average water temperature in Kerry is 9.1°C/48.4°F, the minimum temperature is 8°C/46.4°F, and the maximum is 10.1°C/50.2°F.. Water temperature in Kerry today is 8.7°C/47.7°F. The warmest sea in Greystones in September is 15.7°C/60.3°F, and the coldest sea temperature in September is 13.4°C/56.1°F. Sea water temperature in Kerry is expected to rise to 9.1°C/48.4°F in the next 10 days. Max: 9.9°C / 48.9°F Avg: 8.7°C / 47.7°F Min: 7.6°C / 46.6°F. Today's Portsalon Beach sea temperature is 10.2 ° C. Statistics for 09 Dec (1981–2005) – mean: 10.3 ° C , range: 9.3 ° C to 11.4 ° C The water temperature (10 °C) at Portsalon Beach is quite cold. Historical data. Greystones average February sea temperature. Average water temperature in Greystones in August is 15.1°C/59.2°F and therefore is not suitable for comfortable swimming. Note : At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. AVERAGE SEA TEMPERATURE in February for Greystones (Ireland) 9.1 o C. Temperature range in February: 7.6o C / 10.5o C. Current water temperature: 14.6o C In October, the average sea temperature in Greystones, Ireland, is 14.1°C (57.4°F).