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Portstewart sea temperature today
Portstewart, Causeway Coast and Glens, Northern Ireland. Coastal town.
Latest satellite reading, 28 Oct 2026
12.8 °C
55 °F. Close to the normal for 28 Oct (normal 12.7 °C).
Normal for this date
12.7 °C
2003 to 2014 average for 28 Oct
Change over 7 days
-0.6 °C
Compared with the reading a week earlier
Wetsuit guide (general)
4/3 mm full wetsuit
Band 12 to 15 °C. Boots are worth considering.
Last 30 days at Portstewart
Solid line: daily satellite reading (°C). Dashed line: normal for each date (2003 to 2014 average).
Recent daily readings
| Date | Reading | Normal | Difference |
|---|---|---|---|
| 28 Oct 2026 | 12.8 °C | 12.7 °C | +0.1 |
| 27 Oct 2026 | 12.8 °C | 12.7 °C | +0.0 |
| 26 Oct 2026 | 12.8 °C | 12.8 °C | -0.0 |
| 25 Oct 2026 | 12.7 °C | 12.8 °C | -0.1 |
| 24 Oct 2026 | 12.8 °C | 12.9 °C | -0.1 |
| 23 Oct 2026 | 12.9 °C | 13.0 °C | -0.0 |
| 22 Oct 2026 | 13.1 °C | 12.9 °C | +0.2 |
Normal sea temperature by month at Portstewart
Averages of the satellite analysis for 2003 to 2014. The sea here is normally warmest in August (about 14.5 °C) and coldest in March (about 7.7 °C).
| Month | Average | Lowest day | Highest day |
|---|---|---|---|
| January | 8.7 °C | 8.2 °C | 9.4 °C |
| February | 7.8 °C | 7.6 °C | 8.1 °C |
| March | 7.7 °C | 7.5 °C | 8.0 °C |
| April | 8.7 °C | 8.1 °C | 9.3 °C |
| May | 10.1 °C | 9.3 °C | 11.3 °C |
| June | 12.0 °C | 11.2 °C | 13.1 °C |
| July | 13.7 °C | 12.9 °C | 14.7 °C |
| August | 14.5 °C | 14.2 °C | 14.8 °C |
| September | 14.5 °C | 14.0 °C | 14.8 °C |
| October | 13.2 °C | 12.6 °C | 14.0 °C |
| November | 11.9 °C | 11.2 °C | 12.5 °C |
| December | 10.2 °C | 9.5 °C | 11.1 °C |
Nearby places
| Place | Area | Distance | Latest |
|---|---|---|---|
| Portstewart Strand | Causeway Coast and Glens | 4 km | 12.7 °C |
| Portrush | Causeway Coast and Glens | 4 km | 12.9 °C |
| Benone Beach | Causeway Coast and Glens | 10 km | 12.5 °C |
| Ballycastle | Causeway Coast and Glens | 30 km | 13.3 °C |
| Culdaff | Donegal | 31 km | 12.7 °C |
More: all places in Causeway Coast and Glens, Northern Ireland.
About this reading
The value comes from the satellite analysis grid cell centred at 55.18° N, 6.73° W, about 1 km from the GeoNames point for Portstewart. Each cell is about 1 km across. It is the nearest cell the analysis treats as open sea.
Please note. These are satellite-based estimates of the sea surface temperature on a grid about 1 km wide. Water at the shoreline, in rock pools, estuaries and shallow bays can be several degrees warmer or colder. Readings are usually one to two days old. This is not safety advice: check local lifeguard and coastguard guidance before swimming. Water below about 15 °C can cause cold water shock.