Sunshine over the sea and palms at Ao Pra beach, Koh Mak, Trat Province Thailand
Ao Pra, Koh Mak — dry season sunshine
Climate & seasons

Koh Mak Weather

A month-by-month climate reference for Koh Mak: air temperature, rainfall, sea temperature and the monsoon wind that decides whether speedboats sail — plus a live 7-day forecast. If you are choosing when to book, the best-time-to-visit page compares seasons on price, crowds and openings.

Short answer

Warm all year, dry November to April

Koh Mak weather runs on two seasons. From November to April it is dry, sunny and calm, with highs of 31–34°C and sea around 28–30°C. From May to October the southwest monsoon brings heavy but short afternoon downpours, greener scenery and the lowest prices of the year. For the trade-offs on price, crowds and which resorts stay open, see the best time to visit Koh Mak.

Live forecast

Koh Mak 7-day weather forecast

The next seven days on Koh Mak — daytime high, night low, chance of rain and the wind speed that decides whether speedboats run.

Month by month

Koh Mak weather by month

Average monthly temperature, rainfall and sea temperature on Koh Mak, Thailand
MonthHighNightRainSeaOn the island
January31°C24°Cvery low28°CDriest, calmest month. Best snorkelling visibility around Koh Rang.
February32°C24°Cvery low28°CDry and breezy, flat sea, every boat running.
March33°C26°Clow29°CHeat builds; mornings and late afternoons for sport.
April34°C27°Clow30°CHottest month. Songkran mid-month, warm bath-like sea.
May33°C26°Crising30°CFirst monsoon showers, still mostly sunny days.
June31°C26°Chigh29°CGreen season starts. Heavy bursts, sun in between.
July30°C25°Chigh29°CWettest stretch with the lowest room rates of the year.
August30°C25°Chigh29°CWindier sea; some snorkelling trips cancelled.
September30°C25°Chigh29°CGreenest island, quietest beaches, reduced boat schedule.
October31°C25°Ceasing29°CRain fades through the month; closed resorts reopen.
November31°C24°Clow28°CPeak season begins — dry days, settling sea.
December31°C23°Cvery low28°CCoolest evenings, clear water, busiest weeks at New Year.

Figures are long-term island averages for Koh Mak, Trat Province — useful for planning, not a forecast. Check a live forecast a few days before you travel.

Green season reality

What rain on Koh Mak actually looks like

Monsoon rain here is rarely an all-day write-off. A typical green-season day is bright in the morning, clouds up after lunch, delivers one or two hard downpours, then clears for sunset. Roads dry fast, but the concrete and sand tracks get slippery — go slow on a scooter or e-bike and read the getting around Koh Mak notes first.

Weather & the sea

How weather affects boats and snorkelling

  • Ferries: wind, not rain, cancels crossings. Green-season schedules thin out — check the Koh Mak ferry timetable from Laem Sok and never book a same-day onward flight.
  • Snorkelling: clearest water December to April around Koh Rang and Koh Kham; visibility drops when the swell builds after June.
  • Beaches: Ao Kao and Ao Suan Yai are sheltered enough to swim year round — see the Koh Mak beaches guide.
  • Sport: indoor tennis and pickleball courts at White Sand Beach Resort mean rain or midday heat never cancels a session.
FAQ

Koh Mak weather questions

What is the weather like on Koh Mak?
Koh Mak has a tropical monsoon climate with daytime highs between 30°C and 34°C all year and sea temperatures around 28–30°C. The dry season runs from November to April, and the green (rainy) season from May to October, when rain usually falls as short heavy afternoon downpours rather than all-day grey.
What is the rainiest month on Koh Mak?
July through September is the wettest stretch, with July and August the heaviest. Rain typically comes in bursts of one to three hours, often in the afternoon, with sunshine in between.
What is the hottest month on Koh Mak?
April is the hottest month, with highs around 34°C and high humidity. Plan cycling, tennis, pickleball or Muay Thai for early morning or late afternoon.
How warm is the sea around Koh Mak?
The sea stays between roughly 28°C and 30°C all year, peaking in April and May. Water is warm enough to swim in every month.
Does rain stop the ferry to Koh Mak?
Rain alone rarely stops the boats — wind and swell do. Between June and September crossings are reduced and speedboats can be cancelled at short notice, so leave a buffer day before an onward flight.
When is the best weather for snorkelling on Koh Mak?
December to April, when the wind drops and visibility around the Koh Rang marine park and Koh Kham is at its clearest.
Is there a typhoon or storm risk on Koh Mak?
Koh Mak sits in the Gulf of Thailand and is not on a typhoon track. The main weather risk is squally monsoon wind between June and September, which affects boat schedules more than daily life on the island.