Jamestown Sea Temperature

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

Water temperature in Jamestown right now

Below is the current sea temperature for Jamestown, Saint Helena on 12th July 2025.

22.03° C

(71.65° F)

yesterday: 22.15° C (71.86° F)
a week ago: 21.9° C (71.42° F)

Water at this temperature is very pleasant to swim in and if you tend to wear a wetsuit when swimming, you might consider removing it now to avoid the body overheating.

The average sea temperature for Jamestown on July 12th over the last 10 years is 21.92° C (71.46° F), with a low temperature of 21.1° C (69.98° F) and a high of 22.68° C (72.82° F).

Analysis and forecast for Jamestown water temperatures

The water temperature in Jamestown today is higher than the average temperature of 21.92° C (71.46° F) and the temperature on this day last year, 12th July 2024, was 22.05° C (71.69° F).

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

Date	Temperature (Celsius)	Temperature (Fahrenheit)
July 12	22.03° C	71.65° F
July 11	22.15° C	71.86° F
July 10	21.94° C	71.49° F
July 9	21.98° C	71.56° F
July 8	21.79° C	71.22° F
July 7	21.84° C	71.31° F
July 6	21.84° C	71.31° F
July 5	21.9° C	71.42° F
July 4	22.05° C	71.69° F
July 3	21.81° C	71.26° F
July 2	21.81° C	71.26° F
July 1	21.63° C	70.93° F
June 30	22.02° C	71.64° F
June 29	22.02° C	71.64° F
June 28	22.12° C	71.82° F
June 27	22.12° C	71.82° F
June 26	22.27° C	72.09° F
June 25	22.34° C	72.21° F
June 24	22.4° C	72.32° F
June 23	22.43° C	72.37° F
June 22	22.35° C	72.23° F
June 21	22.47° C	72.45° F
June 20	22.42° C	72.36° F
June 19	22.53° C	72.55° F
June 18	22.59° C	72.66° F
June 17	22.67° C	72.81° F
June 16	22.68° C	72.82° F
June 15	22.68° C	72.82° F
June 14	22.66° C	72.79° F
June 13	22.72° C	72.9° F
June 12	22.79° C	73.02° 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 Jamestown by month

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

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

January February March April May June July August September October November December

Jamestown map and nearby water temperatures

The highest temperature in Saint Helena today is 22.4° C (72.31° F) in Jamestown. The lowest is in Jamestown, where the temperature of the water is 22.4° C (72.31° F).

Why measure sea surface temperatures (SST) in Jamestown?

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

SST is one measure that provides information on the global climate, and it can be used to predict the weather in Jamestown 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 Jamestown 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.

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"Jamestown Sea Temperature". SeaTemperatures.net. Accessed on July 12, 2025. http://seatemperatures.net/africa/saint-helena/jamestown/.
"Jamestown Sea Temperature". SeaTemperatures.net, http://seatemperatures.net/africa/saint-helena/jamestown/. Accessed 12 July, 2025
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