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Jamestown Sea Temperature in December

Saint Helena

November Jamestown year-round → January

Average sea temperature for Jamestown, Saint Helena across December, based on 10 years of daily readings.

Average

22.02° C

High

23.69° C

Low

20.64° C

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

December is the 7th warmest of 12 months at Jamestown. On average the water sits 0.8° than the year-round mean of 22.8° C.

Compared to November, December is 1.1° warmer than (20.89° C in November). By January the water is usually 23.72° C.

Jamestown Day-by-Day Water Temperature in December

10-year low, average and high

20.0° C
21.1° C
22.3° C
23.4° C
24.5° C
1
5
10
15
20
25
31
Day-by-day low and high band with the 10-year daily average through December. Range Average

Each vertical bar above is one day of December. The shaded band covers the range the water has reached on that day across the last 10 years — the lowest reading at the bottom, the highest at the top. The line running through the bars is the daily average over those 10 years, so you can see the typical shape of the month at Jamestown.

A narrow band means the temperature on that day has stayed close to the average year on year. A taller band means it has swung more, often because of changeable weather around that time of year. Hovering a day pulls up its low, average, and high.

December Water Temperature Table for Jamestown

10-year daily averages

Day Average Low High
December 1 21.35° C 20.64° C 22.47° C
December 2 21.38° C 20.77° C 22.5° C
December 3 21.43° C 20.77° C 22.53° C
December 4 21.48° C 20.98° C 22.6° C
December 5 21.53° C 21.01° C 22.69° C
December 6 21.6° C 21.01° C 22.81° C
December 7 21.67° C 21.13° C 22.89° C
December 8 21.73° C 21.18° C 22.95° C
December 9 21.82° C 21.25° C 22.93° C
December 10 21.88° C 21.24° C 22.91° C
December 11 21.81° C 21.19° C 22.94° C
December 12 21.83° C 21.16° C 22.95° C
December 13 21.85° C 21.21° C 22.91° C
December 14 21.85° C 21.19° C 22.9° C
December 15 21.85° C 21.18° C 22.91° C
December 16 21.9° C 21.18° C 23.03° C
December 17 21.94° C 21.18° C 23.24° C
December 18 21.99° C 21.06° C 23.3° C
December 19 22.08° C 21.25° C 23.3° C
December 20 22.16° C 21.41° C 23.27° C
December 21 22.24° C 21.53° C 23.18° C
December 22 22.28° C 21.46° C 23.16° C
December 23 22.36° C 21.55° C 23.16° C
December 24 22.4° C 21.51° C 23.26° C
December 25 22.42° C 21.56° C 23.13° C
December 26 22.47° C 21.71° C 23.11° C
December 27 22.53° C 21.75° C 23.2° C
December 28 22.65° C 21.83° C 23.4° C
December 29 22.67° C 21.85° C 23.5° C
December 30 22.71° C 21.76° C 23.62° C
December 31 22.8° C 21.8° C 23.69° C

Where December Sits in the Year

December highlighted

18.5° C
20.9° C
23.3° C
25.6° C
28.0° C
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
23.72° C
24.85° C
25.4° C
25.13° C
24.35° C
23.16° C
22° C
21.17° C
20.46° C
20.4° C
20.89° C
22.02° C
10-year monthly history for Jamestown. Bars span historical low to high; the line marks the monthly average. Range Average
January → February → March → April → May → June → July → August → September → October → November → December →

Nearby Locations in December

Compare other Saint Helena water for the same month

Jamestown Location

-15.9286, -5.7152

-15.92863, -5.71517 View on OpenStreetMap →

Jamestown sits at -15.9286°N, 5.7152°W, on the coast of Saint Helena. The marker on the map shows the spot the readings on this page come from. It usually sits a short distance from the town centre, out on the open water itself, so the numbers stay tied to the coast rather than a generic point inland.

Coastlines bend, headlands focus the water, and the temperature can run noticeably differently between two beaches that look close together on a map. Comparing nearby locations is a quick way to see how local geography is shaping the readings.

Nearest locations to Jamestown