Month by month
| Month | Sea (°C) | Rain (mm) | Sea state on the west coast |
|---|---|---|---|
| January | 28 | 30 | Calm, clear water |
| February | 28 | 24 | Calm, very good visibility |
| March | 29 | 74 | Calm, some swell |
| April | 30 | 143 | Mostly calm |
| May | 30 | 260 | Waves on the west coast |
| June | 30 | 213 | Rough, red flags common |
| July | 29 | 258 | Rough, red flags common |
| August | 29 | 287 | Rough, strong currents possible |
| September | 29 | 361 | Rough, strong currents |
| October | 29 | 320 | Improving, unpredictable |
| November | 29 | 177 | Calming down, some waves |
| December | 28 | 72 | Calm, clear water |
Underwater visibility
In the dry season, dive and snorkelling sites usually offer clear water, with figures around 15 to 25 m in January according to guides. In the rainy season the water is murkier, sometimes only a few metres: choose sheltered islands or the east coast. See which snorkelling trip in Phuket.
Jellyfish
According to a local guide, the risk is low from November to February, moderate in March-April and October, and higher from May to September, with box jellyfish reported mostly on certain west-coast beaches. Put vinegar on the sting, do not rub it, and see a doctor at the first sign of illness: see health in Phuket. A long-sleeved rash guard lowers the risk.
Which sea trip
For the clearest sea, aim for November to April. The speedboat day trip to the Coral and Racha islands is a good visibility test; compare it in Racha or Coral island. To choose your month, read the best time to visit Phuket.
FAQ
What is the sea temperature in Phuket?
Between 28 and 30 °C all year.
When is the water clearest?
From November to April, especially January and February.
Are there jellyfish in Phuket?
Yes, mostly from May to September on the west coast; the risk is low in the dry season.
La rédaction Phuket Authority, information read on 30 October 2026.
