Similan Island 4 Beach — Sea temperature now
Powdery white-sand beach on Ko Miang.
Very warm water with a light chop and a light breeze — great swimming conditions.
Location
Similan Island 4 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 Similan Island 4 Beach
The sea in Similan Island 4 Beach peaks in April, when the water averages around 30°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 January at around 27°C, when cold-water swimmers dominate the coast.
Similan Island 4 Beach sea temperature history
Long-term climatology for Similan Island 4 Beach shows an annual mean sea temperature of 29°C, ranging from 27°C in winter to 30°C at the summer peak.
The seasonal swing is roughly 3°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 Similan Island 4 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.
Similan Island 4 Beach sea temperature: frequently asked questions
What is the warmest month to swim in Similan Island 4 Beach?
April is the warmest month in Similan Island 4 Beach, when the sea averages about 30°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Similan Island 4 Beach?
The coldest month in Similan Island 4 Beach is typically January, when the water averages around 27°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Similan Island 4 Beach without a wetsuit?
The main swimming season in Similan Island 4 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 Similan Island 4 Beach?
Similan Island 4 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 Similan Island 4 Beach?
The long-term annual mean sea temperature in Similan Island 4 Beach is about 29°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Similan Island 4 Beach?
The live reading at the top of this page shows the current sea temperature in Similan Island 4 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 | 27°C | Hot |
| Feb | 28°C | Hot |
| Mar | 29°C | Hot |
| Apr ⭐ | 30°C | Hot |
| May | 30°C | Hot |
| Jun | 29°C | Hot |
| Jul | 29°C | Hot |
| Aug | 29°C | Hot |
| Sep | 29°C | Hot |
| Oct | 29°C | Hot |
| Nov | 28°C | Hot |
| Dec | 27°C | Hot |