The best time of year to visit Phuket is from December to March.
Phuket has a tropical monsoonal climate. It’s warm all year round, but it’s hottest from April to May and September to October. The September to October period is also the wettest, thanks to the monsoons in the south-west.
This is because it is the north-east monsoon season. The average temperature is from around 24°C to 32°C, and the humidity is at its lowest at this time of the year. However, the hottest weather is from April to May with temperatures from 27°C to 36°C. The humidity is high, making the days feel much hotter, there is the occasional thundery, but short, showers bringing relief to the heat.
The weather in Phuket is usually at its worst in September to early October. These two months see the heaviest rainfall and the seas are at their roughest. This makes it the best time of year for surfers to visit. Even at this time, you can typically get long sunny spells between the showers.
During low season months, you can find the best value offers for accommodations and fewer people. Most return travellers come back in the low season as it is lots quieter, still lovely and warm all the time – the only downside is you could get caught in a shower or two.
The best months for Phuket diving are December until May as this is when we have the lowest currents and very low wind. The underwater visibility does not get really affected by the rain – it is the underwater currents and surface wind that make the most difference – a great place for currents/tides/wind forecast website is WindGuru.