Golden sand
Las Arenas
Las Arenas, Spain · sea 21.7 °C at its warmest, in August

Sea temperature month by month
Monthly means in °C, NOAA OISST v2.1 climatology 1991–2020.
About
La playa de Las Arenas (Areetako Hondartza en euskera), ubicada en el barrio de Las Arenas del municipio vizcaíno de Guecho, País Vasco (España), es una playa con arena.
Questions
How warm is the sea at Las Arenas?
The sea off Las Arenas averages 21.7 °C at its warmest, in August, and 12.5 °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 Las Arenas?
The sea reaches 20 °C or more from July to September. Twenty degrees is where most swimmers stop calling water cold; below it, a wetsuit helps.
Where is Las Arenas?
Las Arenas is on the coast of Las Arenas, Spain, at 43.3270, -3.0175. The map on this site flies straight to it.