Sea temperature in Indonesia
Live water temperatures and swimming conditions across 107 beaches on the Indonesia coast.
Best time to swim in Indonesia
The sea in Indonesia peaks in January, when the water averages around 29°C.
The main swimming season runs from January – December, when surface temperatures stay comfortable for extended sessions.
On average, 12 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
The coldest month is typically August at around 27°C, when cold-water swimmers dominate the coast.
Indonesia sits in the Southern Hemisphere, so the warmest sea coincides with the December–February summer and the coolest with July–August.
Indonesia sea temperature history
Long-term climatology for Indonesia shows an annual mean sea temperature of 29°C, ranging from 27°C in winter to 29°C at the summer peak.
The seasonal swing is roughly 2°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 Indonesia, 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.
Values are area averages; individual beaches vary by exposure and depth.
Indonesia sea temperature: frequently asked questions
What is the warmest month to swim in Indonesia?
January is the warmest month in Indonesia, when the sea averages about 29°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Indonesia?
The coldest month in Indonesia is typically August, when the water averages around 27°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Indonesia without a wetsuit?
The main swimming season in Indonesia runs from January – December — about 12 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.
Do I need a wetsuit in Indonesia?
Indonesia stays warm year-round, so most swimmers never need a wetsuit — a rash guard is usually enough for sun and wildlife protection.
What is the average sea temperature in Indonesia?
The long-term annual mean sea temperature in Indonesia is about 29°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Indonesia?
The live reading at the top of this page shows the current sea temperature in Indonesia, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Coastal regions of Indonesia
Region hubs with live sea temperatures, swim conditions and a beach directory.