The short answer
When to go to Koh Tao
February to April is the most reliable window, with the least rain and calmer conditions for boats and snorkelling. May to September is hot and humid with moderate rain. October to December is the wettest, with November the worst, and ferries and boat trips can be disrupted. Older travellers should prefer February and March and plan outings for early morning.
Month by month
Koh Tao weather by month
| Month | High | Low | Rain | Verdict | What to expect |
|---|---|---|---|---|---|
| January | 29°C | 24°C | 127 mm | Some showers as the wet season ends; seas calming | |
| February | 29°C | 25°C | 64 mm | Driest month; sunny and comfortable | |
| March | 30°C | 25°C | 116 mm | Hot and mostly bright; good for boats | |
| April | 32°C | 26°C | 83 mm | Hotter; plan outings early, rest midday | |
| May | 33°C | 26°C | 132 mm | Hot, humid, rising showers | |
| June | 33°C | 25°C | 134 mm | Warm and humid with showers; fewer visitors | |
| July | 32°C | 25°C | 117 mm | Humid with showers; check boat conditions | |
| August | 32°C | 25°C | 102 mm | Humid with showers; moderate rain | |
| September | 32°C | 25°C | 118 mm | Rain builds; confirm boat services | |
| October | 31°C | 24°C | 295 mm | Wet; boat trips and snorkelling less reliable | |
| November | 30°C | 24°C | 445 mm | Wettest month; ferries and boat trips can be disrupted | |
| December | 29°C | 24°C | 263 mm | Still wet; showers ease late in the month |
Temperatures and rainfall are long-term monthly averages. Check the forecast a few days before you travel.
Seasons at a glance
Koh Tao seasons for families and seniors
The easiest months: February and March
- February: Driest month; sunny and comfortable
- March: Hot and mostly bright; good for boats
Good, with small trade-offs: January and April
- January: Some showers as the wet season ends; seas calming
- April: Hotter; plan outings early, rest midday
Possible, with planning: May, June, July, August, September, October and December
- May: Hot, humid, rising showers
- June: Warm and humid with showers; fewer visitors
- July: Humid with showers; check boat conditions
- August: Humid with showers; moderate rain
- September: Rain builds; confirm boat services
- October: Wet; boat trips and snorkelling less reliable
- December: Still wet; showers ease late in the month
Best avoided with parents or children: November
- November: Wettest month; ferries and boat trips can be disrupted
Useful answers
Best time to visit Koh Tao: FAQs
What is the best month to visit Koh Tao?
February and March are the best months to visit Koh Tao, with January and April also good. February to April is the most reliable window, with the least rain and calmer conditions for boats and snorkelling. May to September is hot and humid with moderate rain. October to December is the wettest, with November the worst, and ferries and boat trips can be disrupted. Older travellers should prefer February and March and plan outings for early morning.
Which months should I avoid in Koh Tao with elderly parents?
November is the month to avoid with older travellers. Wettest month; ferries and boat trips can be disrupted
When does it rain most in Koh Tao?
November is the wettest month, with about 445 mm of rain on average. The hottest month is May, with average highs around 33°C.