Irish Sea Water Temperature Today & Regional Overview
We find every place where you can swim and show you the water temperature there today and throughout the year.
Current Water Temperature
The water temperature in the Irish Sea today ranges from 44°F (Malahide, Republic of Ireland) to 48°F (Glynn, United Kingdom).
As of today, the minimum water temperature in the Irish Sea ranges from 41°F (5°C) to 47°F (8°C). This water temperature is still quite low, and swimming in such conditions may only be comfortable for hardened individuals. It is recommended to limit the time spent in the water to avoid hypothermia. For those not accustomed to cold water, it is better to refrain from swimming. However, if you decide to enter the water, it is advisable to wear a warm wetsuit for protection against the cold.
It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Sea Temperature Trends
Over the past month, the water temperature in the Irish Sea has remained almost unchanged. In general, the sea water temperature remains within the statistical range for this time of year.
Water Temperature and Swimming Conditions Throughout the Year
| Month | Min | Max |
|---|---|---|
| January | 45°F | 52°F |
| February | 43°F | 50°F |
| March | 43°F | 52°F |
| April | 45°F | 54°F |
| May | 45°F | 57°F |
| June | 48°F | 63°F |
| July | 50°F | 66°F |
| August | 54°F | 66°F |
| September | 54°F | 64°F |
| October | 52°F | 61°F |
| November | 50°F | 59°F |
| December | 46°F | 55°F |
The Irish Sea has relatively cool temperate water that varies seasonally and by location. Typical surface temperatures range from about 6–9 °C in winter, gradually warming in spring to roughly 8–13 °C. By summer, coastal waters commonly reach between 13–18 °C, with the warmest readings in sheltered southern bays; in autumn temperatures usually fall to around 10–15 °C as the sea releases stored heat. Local factors such as depth, exposure to Atlantic currents, and tidal mixing mean that northern and more exposed areas tend to be a few degrees cooler than southern or sheltered inlets, and shallow estuaries can warm or cool more quickly than open water.
Swimming Conditions
Swimming in the Irish Sea is permitted and practiced widely, but conditions require caution. The water is often colder than many swimmers expect, so wetsuits are commonly used outside the warmest weeks to reduce hypothermia risk and extend comfort. Strong tides, sudden rips, tidal races and busy shipping lanes pose safety hazards, so swimming is safest at lifeguarded beaches or in designated swimming areas where local conditions are monitored. Water quality can vary with runoff and sewage discharges, so many communities run regular testing and post safety guidance; checking local advisories and tide times is advisable before entering the water. Overall the Irish Sea offers good recreational swimming opportunities for prepared and informed swimmers, particularly in summer, but respect for temperature, tides and local safety measures is essential.