Beach
Mésa Pigádia (strand)
Thira Municipality, Greece · sea 24.4 °C at its warmest, in August

Sea temperature month by month
Monthly means in °C, NOAA OISST v2.1 climatology 1991–2020.
About
beach in Greece
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 Mésa Pigádia (strand)?
The sea off Mésa Pigádia (strand) averages 24.4 °C at its warmest, in August, and 16.1 °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 Mésa Pigádia (strand)?
The sea reaches 20 °C or more from June to October. Twenty degrees is where most swimmers stop calling water cold; below it, a wetsuit helps.
Where is Mésa Pigádia (strand)?
Mésa Pigádia (strand) is on the coast of Thira Municipality, Greece, at 36.3534, 25.3776. The map on this site flies straight to it.