Nai Harn Beach Water Temperature & Swim Forecast
Sheltered south-Phuket family beach.
Very warm water with a light chop and a light breeze — great swimming conditions.
Model estimate · modelled, not a buoy measurement. How accurate is this?
Location
Nai Harn 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.
No wetsuit
At 28.5°C the water is warm enough to swim and surf in just a swimsuit or boardshorts.
Recommendation tuned for Nai Harn Beach's current water temperature. Individual tolerance, wind chill, and session length all matter — when in doubt, size up.
Nai Harn Beach swimming conditions summary
- Water temperature
- 28.5°C
- Water feels
- Bath-warm
- Swimmable today
- Yes — comfortable for most swimmers
- Swim conditions score
- 88/100 · Excellent
- Wetsuit needed
- No wetsuit
- Air temperature
- —
- Waves
- —
- Wind
- —
- UV index
- —
- Average sea temperature (September)
- 29.0 °C
- Warmest months to swim
- March, April, May
At 28.5°C the water is warm enough to swim and surf in just a swimsuit or boardshorts. Model estimate. Water, wave, wind and UV values are Open-Meteo marine/weather model estimates, refreshed hourly — not buoy measurements.
Frequently asked questions
Can I swim at Nai Harn Beach right now?
The sea at Nai Harn Beach is currently 28.5°C — excellent swimming conditions. Most swimmers will find the water comfortable when it's above 22°C; below 18°C feels fresh and a wetsuit is recommended.
What will the sea temperature be at Nai Harn Beach next week?
Based on long-term September averages and the latest marine model, expect the sea around Nai Harn Beach to sit close to 29.0°C over the next 7 days. Check the live 7-day chart above for the exact daily outlook.
When is the best month to swim at Nai Harn Beach?
March – April – May are typically the warmest months to swim at Nai Harn Beach, with sea temperatures at their seasonal peak.
Do I need a wetsuit at Nai Harn Beach?
With water currently at 28.5°C: above 22°C no wetsuit needed; 18–22°C a shorty is comfortable for long swims; 14–18°C a 3/2mm full suit; below 14°C a 4/3mm or thicker.
Can I swim at Nai Harn Beach today?
The sea is currently 28.5°C — excellent swimming conditions. Most swimmers will find it pleasant.
- • Located in Phuket, Thailand (Andaman Sea).
- • Family friendly with calm, accessible water.
- • Live data refreshed hourly from Open-Meteo Marine.
Monthly sea temperature averages
Tap any month to see what to expect — based on regional climatology.
Best time to swim in Nai Harn Beach
The sea in Nai Harn 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.
Nai Harn Beach sea temperature history
Long-term climatology for Nai Harn 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 Nai Harn 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.
Nai Harn Beach sea temperature: frequently asked questions
What is the warmest month to swim in Nai Harn Beach?
April is the warmest month in Nai Harn Beach, when the sea averages about 30°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Nai Harn Beach?
The coldest month in Nai Harn Beach is typically January, when the water averages around 27°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Nai Harn Beach without a wetsuit?
The main swimming season in Nai Harn 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 Nai Harn Beach?
Nai Harn 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 Nai Harn Beach?
The long-term annual mean sea temperature in Nai Harn Beach is about 29°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Nai Harn Beach?
The live reading at the top of this page shows the current sea temperature in Nai Harn 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 |
Nearby beaches
The closest coastline, with live water temperatures.