Seasonal Check
Koh Tao weather by month for remote workers
Twelve months in Koh Tao: the season, average low and high, rainfall and what each month means for remote work.
Best time to be in Koh Tao
Koh Tao month by month
Temperatures and rainfall are long term averages for a typical year, not a forecast. Months marked as best are the ones we would choose to be here.
| Month | Season | Low | High | Rain | For remote work |
|---|---|---|---|---|---|
| January | Between seasons | 24°C | 29°C | 127 mm | The tail of the monsoon: the tourism association still counts January as a monsoon month, and the rain comes in bursts, but the sea is settling and the water is clearing. Rents are inside the December to April band where landlords add 15 to 30 percent, so a lease signed now costs more than the same room in September. Book your first week before you fly and hunt in person after that. |
| FebruaryBest month | Dry season | 25°C | 29°C | 64 mm | The driest month of the year and one of the three the tourism association names as calmest at sea, so crossings run and dive boats go out. Visibility is back at its best from now to May. The catch is water: the island lives on wells, boreholes and tanks, and they start running low from February, so ask a landlord about supply and tank size before you pay a deposit. |
| MarchBest month | Dry season | 25°C | 30°C | 116 mm | The easiest month to live here. Seas are calm, the Chumphon crossing is at its most reliable, and visibility can hit 30 m and more. Heat is building towards the April and May peak and wells are at their lowest, especially in the east coast bays. Morning boat back by noon, desk by 15:00, European calls until 21:00: the schedule that makes this island work. |
| AprilBest month | Dry season | 26°C | 32°C | 83 mm | Island dive schools call April the hottest month: the Ko Samui normals give about 32 C by day, with May a degree hotter, and humidity sits above 80 percent, which is what decides whether you pay for air conditioning and the landlord electricity rate that comes with it. Songkran runs 13 to 15 April: block those three days, keep client calls off the calendar, and keep the laptop indoors, because water gets thrown at everyone on a scooter. |
| MayBest month | Dry season | 26°C | 33°C | 132 mm | Still hot, still clear underwater, with afternoon wind and short bursts of rain arriving on the west coast. When Sairee gets choppy after lunch, Hin Wong, Tanote and the east side stay sheltered. High season pricing ends in April, so this is the first month where a monthly room negotiates down and the coworking desks have space again. |
| June | Summer | 25°C | 33°C | 134 mm | The Andaman coast is under the southwest monsoon and the Gulf is not, which is the whole reason to be on this side of the country in June. Rain arrives in short bursts, rooms sit at low season rates, and the island is quiet before July. Storm outages are more common here than on the mainland, so this is the month to buy the power bank and the small UPS for the router. |
| July | Summer | 25°C | 32°C | 117 mm | The European summer fills the dive schools and the good rooms go first, so lock a monthly rental before July if you want a choice. Power cuts are reported more often at high season peaks and the island internet degrades at busy hours, which matters between 15:00 and 21:00 when you are actually on calls. A coworking membership earns its price this month. |
| August | Summer | 25°C | 32°C | 102 mm | Slightly drier than June or July and still busy. Cafes are full of holiday traffic and most of them close mid afternoon, so working from a bar table stops being a plan. Rents ease again from September, so a lease that ends in August gives you leverage for the next one and a clean exit if you are moving on before the rain. |
| September | Between seasons | 25°C | 32°C | 118 mm | The last calm month: the tourism association lists September alongside February and March for sea state, and prices have come off the summer peak. The unpaved sections of the cross island roads start getting slick from now to December, so ride the Tanote and Hin Wong hills carefully. Decide this month whether you sit out the rain here or move to Bangkok or Chiang Mai. |
| October | Rainy season | 24°C | 31°C | 295 mm | The northeast monsoon arrives and visitor numbers hit their annual low, so accommodation, dive courses and tours all discount. Visibility falls from 30 m and more towards about 10 m. This is also when the Chumphon crossing starts getting cancelled, and Lomprayah normally rebooks you rather than refunding, so never plan a connection with no slack. |
| November | Rainy season | 24°C | 30°C | 445 mm | The wettest month by a wide margin, with roughly a one in two chance of significant rain on any given day. Seas are at their roughest and cancellation risk on the mainland ferry is at its highest, so leave a buffer day before any flight. Rooms are cheap and the island is empty. If you work through it, pay for a place with its own fibre line rather than relying on a cafe. |
| December | Rainy season | 24°C | 29°C | 263 mm | Rain eases through the month but the sea stays big and the crossing stays unreliable into January. December is when rents start climbing again, 15 to 30 percent above the low season rate through to April, and Christmas and New Year are the most expensive weeks of the year for rooms and courses. Book the ferry and the room ahead, not on arrival. |
Where these figures come from
Monthly temperatures and rainfall are the World Meteorological Organization 1991 to 2020 normals for Ko Samui, the nearest long term station to Koh Tao (about 70 km south, same northeast monsoon regime), as reproduced in the Ko Samui climate table on Wikipedia and rounded to whole numbers; rainfall there averages 1,994 mm a year. Koh Tao itself has no published station normals, so read these as the regional pattern, not as a gauge reading at Mae Haad. The Koh Tao Tourism Association describes the local monsoon as November to January with November the wettest month, which matches the Ko Samui rainfall curve with one month of lag at the tail. Sea state, dive visibility, ferry cancellation risk, power cuts and seasonal rents come from the island sources below. For live forecasts and marine warnings in the Gulf of Thailand, check the Thai Meteorological Department at tmd.go.th before you book a crossing.
- Wikipedia, Ko Samui, climate data table (WMO normals 1991 to 2020, nearest station to Koh Tao), accessed .
- Koh Tao Tourism Association, weather (monsoon November to January, sea temperature, visibility, calmest months), accessed .
- Thai Meteorological Department, forecasts and marine warnings for the Gulf of Thailand, accessed .
- Black Turtle Dive, Koh Tao weather (April the hottest month, February to May best visibility, humidity above 80 percent), accessed .
- Wonderland Koh Tao, Koh Tao low season (October the quietest month, November rain odds, discounting), accessed .
- Wonderland Koh Tao, Chumphon to Koh Tao ferry 2026 (cancellation risk October to December, calmest March to May), accessed .
- Wonderland Koh Tao, Koh Tao versus Koh Phangan 2026 (island power supply, high season cuts, peak hour internet), accessed .
- ExplorerTom, Andaman Sea or Gulf of Thailand by month (Gulf islands stay dry through the European summer), accessed .
- BAANLYY, Koh Tao utilities setup 2026 (storm outages, wells low from February to April, drinking water refills), accessed .
- BAANLYY, Koh Tao rental market 2026 (rents 15 to 30 percent higher from December to April, deposits and notice), accessed .
- BAANLYY, Koh Tao getting around 2026 (steep and partly unpaved roads, extra hazard September to December), accessed .
- Theo Courant, Songkran 2026 dates (13 to 15 April nationally), accessed .
Figures on this page last checked .