Koh Mak Weather
Koh Mak sits in the Gulf of Thailand off Trat, so it is warm every single day of the year — the only real variable is rain and wind. Here is the month-by-month picture: temperature, rainfall, sea temperature and what the weather actually changes for boats, snorkelling and sport.
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.
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.
Koh Mak weather by month
| Month | High | Night | Rain | Sea | On the island |
|---|---|---|---|---|---|
| January | 31°C | 24°C | very low | 28°C | Driest, calmest month. Best snorkelling visibility around Koh Rang. |
| February | 32°C | 24°C | very low | 28°C | Dry and breezy, flat sea, every boat running. |
| March | 33°C | 26°C | low | 29°C | Heat builds; mornings and late afternoons for sport. |
| April | 34°C | 27°C | low | 30°C | Hottest month. Songkran mid-month, warm bath-like sea. |
| May | 33°C | 26°C | rising | 30°C | First monsoon showers, still mostly sunny days. |
| June | 31°C | 26°C | high | 29°C | Green season starts. Heavy bursts, sun in between. |
| July | 30°C | 25°C | high | 29°C | Wettest stretch with the lowest room rates of the year. |
| August | 30°C | 25°C | high | 29°C | Windier sea; some snorkelling trips cancelled. |
| September | 30°C | 25°C | high | 29°C | Greenest island, quietest beaches, reduced boat schedule. |
| October | 31°C | 25°C | easing | 29°C | Rain fades through the month; closed resorts reopen. |
| November | 31°C | 24°C | low | 28°C | Peak season begins — dry days, settling sea. |
| December | 31°C | 23°C | very low | 28°C | Coolest 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.
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.
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.