Sea temperature in Uruguay

The sea in Uruguay peaks in January, when the water averages around 28°C.

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

On average, 8 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.

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

The coldest month is typically July at around 18°C, when cold-water swimmers dominate the coast.

Uruguay 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 Uruguay shows an annual mean sea temperature of 23°C, ranging from 18°C in winter to 28°C at the summer peak.

The seasonal swing is roughly 10°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 Uruguay, 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.