Swansea Sea Temperature

Looking to find out what the sea water temperature in Swansea is for today and the next few days? Below are data and charts that will give you information about sea temperatures in Swansea and nearby locations.

Water temperature in Swansea right now

Below is the current sea temperature for Swansea, United Kingdom on January 10, 2026.

Today

Yesterday

A week ago

This water is very cold and can cause pain. We don't recommend you swim in this temperature for anything other than very short swims of 5 to 10 minutes unless you are a very experienced cold water swimmer.

The average sea temperature for Swansea on January 10 over the last 10 years is 8.98° C (48.16° F), with a low temperature of 7.57° C (45.63° F) and a high of 9.64° C (49.35° F).

Analysis and forecast for Swansea water temperatures

The water temperature in Swansea today is the same as the average temperature of 8.98° C (48.16° F) and the temperature on this day last year was 8.98° C (48.16° F).

The chart and table below shows the change in water temperature in Swansea over the last 30 days:

DateTemperature (Celsius)Temperature (Fahrenheit)
January 108.98° C48.16° F
January 98.95° C48.11° F
January 89° C48.19° F
January 79.08° C48.34° F
January 69.04° C48.28° F
January 59.19° C48.53° F
January 49.29° C48.72° F
January 39.33° C48.8° F
January 29.48° C49.06° F
January 19.52° C49.14° F
December 319.52° C49.14° F
December 309.42° C48.96° F
December 299.42° C48.96° F
December 289.3° C48.73° F
December 279.33° C48.8° F
December 269.27° C48.69° F
December 259.39° C48.91° F
December 249.39° C48.91° F
December 239.56° C49.2° F
December 229.66° C49.39° F
December 219.74° C49.53° F
December 209.78° C49.61° F
December 199.77° C49.59° F
December 189.77° C49.59° F
December 179.8° C49.64° F
December 169.81° C49.66° F
December 159.94° C49.89° F
December 1410.08° C50.14° F
December 1310.08° C50.15° F
December 1210.18° C50.32° F

The actual nearshore temperatures may vary by several degrees and this can also be heavily affected by weather. Strong winds can cause cold, deep waters to replace the surface waters that had been warmed by the sun, and heavy rain can also reduce the temperature of the sea surface temperature as well.

Water temperature in Swansea by month

The chart below shows the monthly average water temperature in Swansea.

For more detailed information on how the sea temperature in Swansea changes for each month of the year, choose from the months below.

Swansea map and nearby water temperatures

Swansea sea temperature map

Locations near Swansea

Why measure sea surface temperatures (SST) in Swansea?

The ocean covers about 71% of the Earth's surface, and scientists record the sea surface temperature (SST) of locations such as Swansea because they want to understand and learn how the ocean communicates with the atmosphere of Earth.

SST is one measure that provides information on the global climate, and it can be used to predict the weather in Swansea as well as atmospheric model simulations and to study marine ecosystems in the area.

Data source and citation

Raw data for the calculations made to find the sea surface temperature in Swansea comes from the National Oceanic and Atmospheric Administration (NOAA) and their 1/4° daily Optimum Interpolation Sea Surface Temperature.

The water temperature data is constructed by combining observations from different platforms (satellites, ships, buoys, and Argo floats) on a regular global grid. A spatially complete sea surface temperature map is then built by interpolating to fill in gaps in the data.

If you'd like to use any of the information above in the format it is presented, please use the citation tool below.