Koh Samui in March: Weather, Season and What to Do

Is Koh Samui worth visiting in March? Yes, if you can handle the heat: March is still peak season, with calm seas and little rain, but noticeably warmer than January and February. If you seek shade at midday and drink enough water, you'll get one of the most reliable travel months of the year.

At a glance

Weather in March

March stays dry — around 5 rain days and roughly 120mm of rainfall, only a little more than record-dry February — but temperatures climb noticeably. With an average of 30°C during the day, it's the warmest month of peak season, and nights barely cool off at around 25°C. The sea around the island stays mostly calm, with the occasional short afternoon shower bringing a bit of relief in the evening. For more on the overall climate pattern, see our article Koh Samui weather and the truth about the rainy season.

What you can do in March – and what you can't

Calm seas make March a good month for the half-day trip to see the pink dolphins off Khanom on the mainland opposite Koh Samui, combined with lunch, snorkelling at Koh Tan and a stop at Pig Island:

from 1,850 THBKoh Samui Pink Dolphin tour Khanom★★★★★4.79 from 106 reviews

If you prefer something more exclusive, book the small longtail group to Pig Island and Koh Tan, with a maximum of twelve people on board:

from 1,750 THBPig Island VIP Snorkeling Longtail Boat Koh Mudsum & Koh Tan★★★★★4.65 from 79 reviews

Ang Thong National Park also keeps running reliably through March. In the midday heat, it's worth taking a shaded break or picking an air-conditioned option — a temple tour, a shopping mall, or a night market once it cools down in the evening. More ideas in our Top 10 rainy day activities, which double as good heat-break options too.

For beach days in March, timing matters: mornings are still comfortable on most coasts, but between noon and 3pm direct sun on Chaweng or Lamai gets uncomfortable fast. Shadier alternatives are the palm-lined stretches at Bophut and Maenam in the north, or an early start before the heat builds. If this is your first trip to Koh Samui in March, pack more sun cream than you would for a European summer holiday — UV levels stay high year-round this close to the equator.

Festivals and events in March

The Full Moon Party on neighbouring Koh Phangan is calculated to fall on Monday, 22 March 2027, running as usual from around 21:00 to sunrise on Haad Rin Beach — the date follows the lunar calendar, so check again closer to your trip.

Koh Samui itself gets sporty in March: the Samui Open Beach Volleyball Tournament at Central Festival Samui on Chaweng Beach held its 8th edition from 26 to 29 March 2026, with matches daily from 9am to 9pm and semi-finals and finals on the last day. The exact 2027 date wasn't confirmed at the time of checking, but expect a similar period in late March. More on this and other events in our Top 10 events in Thailand.

Fruit in season

March is a strong month for fruit: watermelon hits its peak now, mango season is heading into its best stretch between March and June, and pineapple also turns sweetest from now through June. The main cantaloupe melon harvest enters its final phase. More seasonal timings in our Top 10 fruits in Thailand.

Frequently asked questions

Does it rain a lot on Koh Samui in March?

No, with around 5 rain days and about 120mm of rainfall, March stays one of the driest months of the year — only a little more than record-dry February.

Is March a good time to visit Koh Samui?

Yes, climate- and sea-wise it's still one of the best times of year. The main difference from January and February is that it gets noticeably hotter, averaging around 30°C during the day.

How hot does it get on Koh Samui in March?

Around 30°C during the day and 25°C at night on average — the warmest month of peak season, though not yet the hottest month of the year. That usually follows in April.

Is the sea calm enough for boat trips in March?

Yes, the sea stays mostly calm through March, and cancellations for wind or swell are rare. That makes it a good month for trips to Ang Thong National Park, Pig Island, or the pink dolphins near Khanom.

See what comes next in April, the hottest month of the year; before that, the air was still a touch cooler in February. For the full-year overview, read The best time to visit Koh Samui, and for every festival across the year, see our Top 10 events in Thailand.