Ang Thong Marine Park Closed? Day Trips That Still Run in November & December

Every year Mu Ko Ang Thong National Marine Park, the 42-island archipelago west of Koh Samui, closes to visitors through the worst of the north-east monsoon. If your holiday falls in November or the first half of December, you cannot do the classic Ang Thong day (the Emerald Lake, the viewpoint climb, kayaking under the cliffs). Most other days out still run. Below are the official dates, exactly what is shut and what to do instead.

Is Ang Thong closed?	Yes. Ang Thong is closed to tourism and overnight stays from 1 November to 15 December 2026, under the Department of National Parks’ official closure list for 2026. It is due to reopen on 16 December 2026.
What is closed	The whole park: the Ao Kha park office beach on Koh Wua Ta Lap, the Thale Nai (Emerald Lake) area, the main beaches, the bungalows and the campsite
Do the dates change?	They are set each year, but the same 1 November–15 December window applied in 2020, 2024, 2025 and 2026. The park can also close at short notice in rough seas
Best alternatives	A south-coast island day (Five Islands, Koh Tan, Pig Island) when the sea allows. If it doesn’t, a land day by 4×4 or at an elephant sanctuary

When is Ang Thong closed? The official 2026 dates

Once a year, Thailand’s Department of National Parks, Wildlife and Plant Conservation (DNP) publishes a single announcement listing the seasonal closures for every national park. The 2026 announcement was signed on 18 December 2025 and published in the Royal Gazette. It lists Mu Ko Ang Thong (entry 31, Surat Thani province) as closed from 1 November to 15 December.

The entry names Ao Kha beach (the park office) and Koh Wua Ta Lap, Hat Sam Sao, Thale Nai, Hat Na Thap, Hat Tham Rang, the Zone 1 bungalows and the Wua Ta Lap campsite. Tourism and overnight stays are closed in full. So for those six and a half weeks no tour boat goes into the park, whichever operator you ask.

Has it always been 1 November to 15 December?

In recent years, yes. The same window was announced for 2020, listed for 2024 and reported for 2025. You may still find other dates online. The park’s own profile on the DNP website, for instance, gives a shorter closure of 1–30 November. Go by the annual announcement, and if you are reading this after 2026, check that year’s list.

Short-notice closures outside the window

The park can also shut for a day or more when the Gulf of Thailand is rough. On 8 January 2026, trips into the park were suspended for one day after warnings of waves of 2–3 metres, as MGR Online reported. Planning Ang Thong for late December or January? Keep a spare day free.

What November and December are like at sea

The park closes because of the weather. November is Koh Samui’s wettest month. Going by World Meteorological Organization averages for 1991–2020, the island’s weather station records about 445 mm of rain in November, spread over around 16–17 days with at least 1 mm of rain. December averages about 263 mm over 11–12 days. February, by contrast, averages about 64 mm (WMO climate normals for Ko Samui).

For boats, the wind matters more than the rain. In its November 2025 weather summary, the Thai Meteorological Department noted that the north-east monsoon covered the Gulf of Thailand for almost the whole month and became rather strong towards the end. The north-east wind builds waves across the Gulf, and the longer open-water crossings feel it most.

That does not make every day stormy. Averages hide sunny spells and calm mornings, and some years are drier than others. But any boat trip at this time of year depends on the forecast for that particular day.

Day trips that still run in November and December

Nothing below is a like-for-like swap for the park’s viewpoint and marine lake. With Ang Thong closed, these are the better ways to spend a day, and the boat trips still depend on the weather on the day.

1. A south-coast island day: Five Islands, Koh Tan and Pig Island

Instead of heading west into open water, this day stays off Samui’s south coast and links three nearby stops. You see the limestone stacks of the Five Islands, snorkel at Koh Tan and meet the beach pigs of Pig Island (Koh Madsum). The crossings are shorter, and with no climbing anywhere it suits mixed groups.

On the Samui Journey 1-Day Catamaran, pickup is between about 9:00 and 9:40 AM depending on your hotel area, and you are back at your hotel at around 4:30 PM. The boat leaves from Bang Kao Pier. Lunch, drinks, accident insurance and hotel transfers are included, as are the banana boat, springboard, floating sea pool and Thai massage on board. All of those are included in the price. The captain is licensed and has more than 10 years’ experience. Everyone gets a life jacket, and there is a first-aid kit on board.

Two policies matter more than usual at this time of year.

• Weather. If it is not safe to sail, your trip moves to a new date first. If that date is also hit, you get a full refund.
• Minimum numbers. The catamaran needs at least 40 guests to sail. If it doesn’t fill, you choose between a new date and a full refund.

To be clear, this trip does not go to Ang Thong. It is a different, gentler kind of island day.

2. A speedboat or longtail to Koh Tan and Pig Island

Smaller boats run to the same southern islands from Thong Krut on the south-west coast. They are quicker and more flexible. A small, fast boat also feels choppy water far more than a large one, so save them for calm days. Going independently? Bring cash for the Pig Island landing fee, which one Samui operator lists at ฿50 per adult. Check there are life jackets in the right sizes before you leave the jetty.

3. A 4×4 island day on land

When the sea is too rough for any boat, head inland. The Explore the Real Samui 4×4 Island Safari costs from ฿1,950 per adult and ฿1,650 per child aged 5–11, and under-5s go free. The trip page has the current itinerary. Rain makes a land day wetter, but it rarely stops one altogether.

4. An ethical elephant visit

Samui Elephant Kingdom is a sanctuary that Samui Journey supports and books visits to (it does not own it). Prices are ฿3,000 per adult and ฿1,700 per child aged 5–11, and under-5s go free. Comparing sanctuaries? Our guide to choosing an ethical elephant sanctuary explains what to look for.

5. Ang Thong itself, from 16 December

If your stay runs past mid-December, you may still get to see the park. Book it for late in your trip, so there is room to reschedule if the first weeks after reopening bring rough seas. Can’t decide between island days? Our Ang Thong or Pig Island comparison sets out the differences in effort, time at sea and who each trip suits.

How to plan a boat day during the closure

• Book your boat day early in your stay. If the weather forces a change, you still have days left to move it.
• Watch the wind more than the rain. A grey, still morning can be better at sea than a bright, windy one.
• Read the policies before paying. Ask what happens if the weather turns, if the boat does not fill, and how late you can cancel. With Samui Journey you can cancel free up to 24 hours before pickup. Later cancellations and no-shows are non-refundable.
• Have a land plan ready. Our list of rainy-day ideas for Koh Samui covers what to do when the sea says no.
• Prepare for motion. If you get seasick easily, talk to a pharmacist before the trip and sit in the middle of the boat.

FAQ