- The Ang Thong rainy season falls in October and the second half of December, and tours still run on most days.
- The national park is usually closed every year from 1 November to 15 December, so no tours can be booked for those dates.
- Only the tour company and the captain decide about the weather, and they can change the route, the order of stops or cancel the trip.
- If the tour company cancels for weather, you choose a new date or a full refund, including the 6% card fee.
- The big boat (from ฿1100) and the Red Baron (฿3700) are smoother on a rough sea than any speedboat.
It is 06:30 in October, the palms outside your bungalow are dripping and the sky over the sea is the colour of wet cement. Your pickup is in an hour and you are wondering whether the boat will even leave. This is the most common question I get in the Ang Thong rainy season, and the honest answer is usually: yes, it leaves, but the day may look a little different from the brochure.
Below is what really changes in the wet months, who makes the call on bad days, what the booking terms say about refunds, and which boat to choose if the sea worries you.
What does the Ang Thong rainy season actually mean?
The Ang Thong rainy season means two short windows: October and the second half of December, after the park reopens. Tours run in both, but on rough days the captain can change the route or cancel the trip.
Koh Samui and the Gulf of Thailand do not follow the same rhythm as Phuket or the Andaman coast. Here the heavy weather comes late in the year, when the north-east monsoon arrives. That is also why the national park takes its annual break right in the middle of it.
Rain here rarely means a grey drizzle all day. More often it is a heavy shower that comes in fast, soaks everything for half an hour and moves on. The problem for a boat trip is not the rain itself: it is the wind that comes with it and the waves the wind builds up between Samui and the islands.
If you want the bigger picture of the park first, the islands, the fee and the seasons, start with the main Ang Thong guide and come back here for the wet-weather details.
Which months are wet, and when is Ang Thong closed?
October and late December are the wet months, and the park is usually closed every year from 1 November to 15 December to let nature recover. During the closure the park sells no tickets and no tours run, so those dates cannot be booked at all.
The exact closing and reopening dates are announced by the national park each year, so if you are planning around mid-December, ask about the date when you book. There is a separate article on what the November to mid-December closure means for your plans, so here I will only put the whole year in one table.
| Period | Park | What to expect at sea |
|---|---|---|
| January to September | Open | Usually calm sea and clear water; short showers are possible but tours run normally |
| October | Open | Rainy season: tours run, but on rough days the captain may change the route or cancel |
| 1 November to 15 December | Usually closed | No tours, no tickets, cannot be booked |
| Second half of December | Reopens around 15 December | Still the rainy season: rougher days are possible and the program can change |
My personal view: early October is often still pleasant, and the closer you get to the end of the month, the more you should keep a spare day in your plans. Late December is a lottery too, with the added pressure that it is a busy holiday period on Samui.
What happens to the sea and the program on a wet day?
On a wet day the sea between Samui and the park gets choppier, the water around the reefs turns cloudier and the captain makes the final call on every stop. You may visit the same islands in a different order, spend less time at one place or skip a stop that is not safe.
The crossing is about 28 km. On a calm morning a speedboat does it in about 40 minutes and feels like a fast ride over glass. On a rough October morning the same boat slams into the waves, spray comes over the side and you hold on to the bench in front of you.
Inside the park things are usually calmer, because the islands break up the swell. The parts of the day that suffer most are these:
- Snorkeling. After rain or strong wind the water can be cloudy, so the reef looks dull or the stop is moved to a more sheltered bay.
- Kayaking. In October and after the reopening in mid-December, kayaking may be shortened or cancelled by the captain if the sea is rough.
- The stairs and trails. The stairway to the Emerald Lake viewpoint and the steep 500-meter trail on Wua Ta Lap are slippery when wet.
- The return trip. If the wind picks up in the afternoon, the boat may leave the last island earlier.
None of this is a disaster. You still see the cliffs, the green lake and the langurs. You just accept that the timetable is a plan, not a promise.
Who cancels an Ang Thong tour for bad weather?
Only the tour company and the captain decide about the weather. Neither you nor the booking agent can overrule them, and that is how it should be: they look at the wind and the sea and decide whether the crossing is safe.
The tours are run by licensed local boat operators. We are the travel agency that sells the tours and looks after the guests, so if the operator calls the day off, we are the ones who contact you and sort out the next step.
A practical point: rain at your hotel in Chaweng tells you very little about the sea between Samui and the park. I have seen pouring rain in the morning turn into a perfectly good day in the park. If the operator has not cancelled, go to the pickup.
What do you get back if the tour is cancelled or you cancel?
If the tour company cancels for weather, you choose a new date or a full refund, including the 6% card fee. If you cancel yourself, the rules depend on how far ahead you do it.
Here is how booking works first. The request on the website is free and no payment is taken. A manager contacts you by WhatsApp or email, confirms the details and sends a payment link for a prepayment, usually 50%. Card payments go through Stripe with a 6% card fee added, and the rest is paid on the day of the tour.
| Situation | What happens to your prepayment |
|---|---|
| The tour company cancels because of weather | New date or full refund, card fee included |
| You cancel 5 days or more before the tour | Refund minus the 6% card fee |
| You cancel less than 5 days before the tour | No refund |
| Illness or injury with a hospital certificate | Refund minus the card fee |
| Kayaking on the speedboat tour is skipped or cancelled for weather | The price does not change |
The full wording is on the cancellation policy page, and it is worth reading before you pay. The key thing for the rainy season: do not cancel on your own because you saw a gloomy forecast. If you cancel late, you lose the prepayment; if the operator cancels, you lose nothing.
Which Ang Thong boats are smoother on a rough sea?
The big tourist boat and the Red Baron sailing junk are the smoothest. Speedboats feel the waves the most, whether it is a regular group boat, the VIP speedboat or a private charter.
The big boat tour leaves daily from Nathon Pier at 08:30 and takes about an hour and a half to reach the first island, twice as long as a speedboat. In return it rolls far less, has a shaded deck and room to walk around. It costs ฿1100 per adult, or ฿1500 with kayaks, plus the park fee of ฿300 per adult.
The Red Baron is a 30-meter traditional sailing junk with red sails, sailing to Ang Thong on Wednesday and Saturday for ฿3700 per adult with the park fee included. A long, heavy wooden boat moving at a slow pace is a much gentler ride than a speedboat bouncing over the same waves.
Speedboats are still the right choice for many people, even in October. The regular speedboat tour (฿1890) gets you there fast, and on a good day that is a huge advantage. Just sit in the back half of the boat, where the bounce is softer, and take a seasickness tablet before you board if you are prone to it. For more on that, read which boat to choose and where to sit if you get seasick.
Is Ang Thong worth visiting in the rainy season?
Yes, if your dates are fixed and you go in with flexible expectations. October and late December are still open months, the islands are just as dramatic in moody light, and a rainy-season day can turn out bright and calm.
Where I would think twice: if this is your only free day on Samui and a cancellation would mean no Ang Thong at all, book for the first days of your stay. That way, if the operator calls it off, you still have time for a new date.
I would also be honest with yourself about seasickness. If a rough ride ruins your day, the big boat or the Red Baron are worth the extra hours at sea. If you are travelling with small children, the stable big boat is the calmer choice in these months too.
The big boat suits budget travellers and anyone who fears the waves, the Red Baron suits those who want a slow, comfortable day with meals on board, and the speedboat suits people who want the most time on the islands and do not mind a bumpy crossing.
- Days
- Daily
- Time
- 07:30-17:00
- Boat
- Large tourist boat
- Park fee
- ฿300 extra
- Days
- Wed, Sat
- Time
- 07:30-19:00
- Boat
- Traditional sailing junk
- Park fee
- Included
- Days
- Daily
- Time
- 07:40-16:30
- Boat
- Shared speedboat
- Park fee
- ฿300 extra
The VIP speedboat (Tuesday, Thursday and Saturday, up to 16 guests, ฿3890 with the park fee included) is a good small-group option in the calm months. In the wet season it is still a speedboat, so it feels the waves like any other. The private Pearl charter (฿39,000 for up to 6 guests) gives you the most flexibility on timing, but it is also a speedboat.
How to plan an Ang Thong trip in October or late December
A little planning takes most of the stress out of a rainy-season trip. Book early in your stay and keep a spare day: that single habit solves most problems.
- Book the tour for your first or second free day on Samui, so a weather cancellation can be moved to a new date.
- Leave the decision to the operator: go to the pickup unless you are told the tour is cancelled.
- Wear shoes with grip for the viewpoint stairs. Flip-flops on wet steps are a bad idea.
- Bring a waterproof pouch for your phone and a light layer: wind and spray on a speedboat can feel cool when you are wet.
- Take cash for the park fee (฿300 per adult, ฿150 per child) unless your tour includes it, as the VIP speedboat and the Red Baron do.
- Carry a photo of your passport: the number is needed for the insurance at registration.
- If you get seasick, choose the big boat or the Red Baron, or take a tablet before a speedboat trip.
And for planning your dates: from January to September the sea is usually calm and the water clear, so if you have a choice, those months are the safer bet. If you do not, October and the second half of December still give you a good chance of a fine day in the park.
Questions and answers
Do Ang Thong tours run in October?
Yes, the park is open in October and tours run on most days. It is the rainy season, so on rough days the captain may change the route, shorten some stops or cancel the trip.
Can I visit Ang Thong in November?
No. The national park is usually closed every year from 1 November to 15 December to let nature recover. The park sells no tickets for these dates and no tours run, so they cannot be booked.
What happens to my money if the tour is cancelled for weather?
If the tour company cancels because of the weather, you choose a new date or a full refund, and the 6% card fee is refunded too. Nothing is lost on your side.
Can I cancel myself if the forecast looks bad?
You can, but the normal rules apply: 5 days or more before the tour the prepayment is refunded minus the 6% card fee, and later there is no refund. It is usually better to wait for the operator's decision.
Is the water clear for snorkeling in the rainy season?
Often less clear than in the dry months. After rain or strong wind the water around the reefs can be cloudy, and the captain may move the stop to a more sheltered spot. The clearest water is usually from January to September.
Which Ang Thong tour is best if I get seasick?
The big tourist boat is the most stable of the tours, and the Red Baron sailing junk is also much smoother than a speedboat. Speedboats feel the waves the most, especially in October and late December.
Is kayaking possible in the rainy season?
Often yes, but on rough days the captain may shorten or cancel it. On the speedboat tour kayaking is included, and skipping it or a weather cancellation does not change the price.
Facts checked against our tour pages on 8 November 2026. Prices and days can change: your manager confirms them when you book.
