Las Grutas Water Temperature & Swim Forecast

The sea in Las Grutas peaks in January, when the water averages around 24°C.

The main swimming season runs from December – March, when surface temperatures stay comfortable for extended sessions.

On average, 4 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.

Shoulder months like November and April are noticeably cooler but often quieter, with fewer crowds and steadier weather.

Outside peak season the water drops toward 14°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.

The coldest month is typically August at around 12°C, when cold-water swimmers dominate the coast.

Las Grutas sits in the Southern Hemisphere, so the warmest sea coincides with the December–February summer and the coolest with July–August.

Long-term climatology for Las Grutas shows an annual mean sea temperature of 18°C, ranging from 12°C in winter to 24°C at the summer peak.

The seasonal swing is roughly 12°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.

Recent decades have trended slightly warmer at Las Grutas, in line with regional sea-surface temperature records for the wider basin.

Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.