Beach
Plage de Pontaillac
Royan, France · sea 20.7 °C at its warmest, in August

Sea temperature month by month
10.7Jan
9.9Feb
10.6Mar
12.5Apr
15May
17.9Jun
20Jul
20.7Aug
19.3Sep
17.3Oct
14.7Nov
12.2Dec
Monthly means in °C, NOAA OISST v2.1 climatology 1991–2020.
Wikipedia has no article about this beach yet. It is on the atlas from its Wikidata record and its photograph.
Questions
How warm is the sea at Plage de Pontaillac?
The sea off Plage de Pontaillac averages 20.7 °C at its warmest, in August, and 9.9 °C at its coolest. These are monthly means from NOAA's OISST v2.1 satellite and buoy record for 1991 to 2020, sampled at the beach's own coordinates.
When can you swim at Plage de Pontaillac?
The sea reaches 20 °C or more from July to August. Twenty degrees is where most swimmers stop calling water cold; below it, a wetsuit helps.
Where is Plage de Pontaillac?
Plage de Pontaillac is on the coast of Royan, France, at 45.6267, -1.0518. The map on this site flies straight to it.