Beach
Ribeiro do Cavalo Beach
Sesimbra, Portugal · sea 19 °C at its warmest, in September

Sea temperature month by month
15.4Jan
14.8Feb
14.9Mar
15.6Apr
16.6May
18Jun
18.5Jul
18.9Aug
19Sep
18.4Oct
17.3Nov
16.2Dec
Monthly means in °C, NOAA OISST v2.1 climatology 1991–2020.
About
Beach in Sesimbra, Portugal
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 Ribeiro do Cavalo Beach?
The sea off Ribeiro do Cavalo Beach averages 19 °C at its warmest, in September, and 14.8 °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 Ribeiro do Cavalo Beach?
The sea here never averages 20 °C in any month, so swimming means cold water all year. Some people do it anyway.
Where is Ribeiro do Cavalo Beach?
Ribeiro do Cavalo Beach is on the coast of Sesimbra, Portugal, at 38.4327, -9.1303. The map on this site flies straight to it.