Mertasari Beach — Sea temperature now
South Sanur beach with a boardwalk.
Very warm water with a light chop and a light breeze — great swimming conditions.
Location
Mertasari Beach on the map, with nearby beaches and live sea temperatures.
7-day forecast
Water, air, waves, wind and UV outlook for the week ahead.
Monthly sea temperature averages
Typical year-round water temperature, based on regional climatology.
Best time to swim in Mertasari Beach
The sea in Mertasari Beach 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 July at around 27°C, when cold-water swimmers dominate the coast.
Mertasari Beach sits in the Southern Hemisphere, so the warmest sea coincides with the December–February summer and the coolest with July–August.
Mertasari Beach sea temperature history
Long-term climatology for Mertasari Beach shows an annual mean sea temperature of 28°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 Mertasari Beach, 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.
Mertasari Beach sea temperature: frequently asked questions
What is the warmest month to swim in Mertasari Beach?
January is the warmest month in Mertasari Beach, when the sea averages about 29°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Mertasari Beach?
The coldest month in Mertasari Beach is typically July, when the water averages around 27°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Mertasari Beach without a wetsuit?
The main swimming season in Mertasari Beach 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 Mertasari Beach?
Mertasari Beach 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 Mertasari Beach?
The long-term annual mean sea temperature in Mertasari Beach is about 28°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Mertasari Beach?
The live reading at the top of this page shows the current sea temperature in Mertasari Beach, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Year-round sea temperature
Best swim months: Jan – Feb – Mar – Apr – May – Jun – Jul – Aug – Sep – Oct – Nov – Dec
| Month | Sea | Comfort |
|---|---|---|
| Jan ⭐ | 29°C | Hot |
| Feb | 29°C | Hot |
| Mar | 29°C | Hot |
| Apr | 29°C | Hot |
| May | 29°C | Hot |
| Jun | 28°C | Hot |
| Jul | 27°C | Hot |
| Aug | 27°C | Hot |
| Sep | 27°C | Hot |
| Oct | 28°C | Hot |
| Nov | 29°C | Hot |
| Dec | 29°C | Hot |