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Mu Ko Similan National Park reopens for the 2026-27 season on Thursday 15 October 2026 and stays open until Saturday 15 May 2027. Thailand’s Department of National Parks (DNP) closes it every year from 16 May to 14 October. The DNP said on 10 August 2026 that the park is open for day trips and scuba diving only, with no overnight stays. Most boats leave from Thap Lamu Pier in Phang Nga. Foreign visitors pay 500 baht per adult and 250 baht per child under DNP rates in effect since 7 June 2022; no later change was found.
Last checked: 6 October 2026. This guide is put together from DNP pages and named news reports. It is not based on a visit. Anything that can change has a source and a date next to it.
Similan Islands open season 2026-27: the dates
| What | Date | Source |
|---|---|---|
| First day of the 2026-27 season | Thursday 15 October 2026 | DNP park page (open 15 October to 15 May every year); DNP news, 7 and 10 August 2026 |
| Last day of the season | Saturday 15 May 2027 | DNP park page |
| Annual closure | 16 May to 14 October | DNP park page; Thai PBS, 18 May 2026 |
The Nation (26 May 2026) described this year’s closure as running “from May 15 to October 15”. The DNP’s own page says 16 May to 14 October, and Thai PBS reported the same dates. All sources agree on 15 October as the first open day. Weather can still cancel boats, so check with your operator close to departure.
Rules for the 2026-27 season
Day trips only, no overnight stays
The DNP banned overnight stays on the Similan Islands in an announcement dated 4 October 2018 and published in the Royal Gazette on 8 October 2018. It repeated this on 5 August 2026 (reported by Thai PBS) and again on 10 August 2026, when it said the park will open from 15 October to 15 May for day trips and scuba diving only. The old island bungalows are now staff housing. Divers who want nights at sea use liveaboard boats.
Daily visitor cap
A DNP announcement dated 9 October 2018 limited the park to 3,850 visitors a day, with no more than 525 scuba divers a day. The Supreme Administrative Court upheld the DNP’s power to set it in March 2019 (Thai PBS, 29 March 2019). At the start of the 2025-26 season the park chief again quoted a maximum of 3,850 visitors a day (Thai PBS, 15 October 2025). No 2026-27 notice giving a different number was found on 6 October 2026, so 3,850 is the latest figure on record, not a confirmed number for this season.
Koh Tachai is still closed
Koh Tachai, the northern island added to the park in 1988, is not open to tourists. In January 2026 the marine national parks advisory committee said there was not enough scientific data to reopen it after more than nine years of closure (Khaosod, 14 January 2026). In March 2026 the DNP reported green turtles hatching there. No reopening date had been announced by 6 October 2026, so be wary of any tour that lists a Koh Tachai landing.
E-tickets for every visitor
Since 15 October 2025, every visitor, Thai or foreign, has needed a DNP e-ticket. Foreigners register with a passport number. The DNP’s May 2025 notice said tickets can be bought in advance or on the day until 8:00 a.m., when the park makes its final headcount. The same notice set fines of 5,000, 20,000 and 100,000 baht for tour companies that declare the wrong passenger numbers or nationalities. No 2026-27 update to these rules was found. Most tour companies buy the ticket for you, so give them the details exactly as they appear in your passport.
Behaviour on the reef
Ahead of the 2025-26 season the park asked visitors not to touch or stand on coral, not to feed marine animals, to take rubbish back with them and to use reef-safe sunscreen. It also set no-dive zones where marine animals breed (Thai PBS, 15 October 2025).
How to visit the Similan Islands
The DNP does not run boats to the islands. Private companies do. These details come from the DNP’s English park page.
- Main pier: Thap Lamu Pier in Thai Mueang district, Phang Nga, about 70 km from the islands. By road, it is about 5 km from the Ban Lam Kaen junction on Highway 4.
- Crossing time: about 1 hour 30 minutes by speedboat to Ko Miang (Island 4), where the park headquarters are. Thai PBS gave 1.5 to 2 hours. Boats that stop at several islands take longer.
- Scheduled boat: the DNP page mentions a scheduled boat that leaves Thap Lamu between 8 and 9 a.m. and comes back at 3 p.m. The page is undated, so ask about this at the pier rather than counting on it.
- By air: fly into Phuket and go by bus or van to Thap Lamu, which the DNP puts at about 100 km away.
- By bus: take a Ranong or Phang Nga bus from Bangkok’s Southern Bus Terminal, get off at the Thap Lamu junction and take a taxi to the pier.
From Phuket
The DNP lists Patong Pier in Phuket as the second gateway, about 90 km from the islands. From Phuket you face either a longer boat ride or a road transfer north to Thap Lamu. Tour sellers also advertise hotel pickups in Khao Lak and Phuket. Pickup areas differ by company, and no official source lists them.
Tour and speedboat prices
The DNP says the fare and what it includes depend on the type of boat. No official price list exists, and this guide does not quote any tour or speedboat prices because none could be verified. When you compare offers, ask how many snorkelling stops and island landings you get and what time pickup is, along with the checklist points below.
Best time to go within the season
The park page splits the year into a hot season from mid-February to May and a rainy season from mid-May to October. It says the southwest monsoon can bring heavy rain and strong waves, which is why the park closes. The open season therefore falls in the drier half of the year. The first and last weeks sit next to the rainy season, so a spare day in your plans helps if a boat is cancelled.
Opening day is not necessarily the busiest. On opening day in 2025 the park counted 2,027 visitors (1,831 foreign, 196 Thai), well below the 3,850 cap (Thai PBS, 15 October 2025). The park chief also said underwater visibility was over 30 metres that day. That was one day in one year, not a promise for this season. Over the whole 2025-26 season the park reported more than 400,000 visitors (The Nation, 26 May 2026). Spread over the 213 open days, that averages roughly 1,900 a day, which is our own estimate. Peak days are likely busier, but no daily figures have been published.
Who should skip it
A Similan day trip means two open-sea crossings of up to two hours each. If you get seasick easily, want a short and easy outing, or are travelling between 16 May and 14 October, skip it. The trip suits snorkellers and divers who are happy with an early start and a long day.
Checklist before you book
- Your date falls between 15 October 2026 and 15 May 2027.
- The operator has your passport details for the DNP e-ticket.
- The quote says whether the park fee is included.
- No Koh Tachai landing and no overnight stay on the islands are promised.
- You know the bad-weather cancellation and refund policy.
FAQ
When do the Similan Islands open in 2026?
The park opens on 15 October 2026 and closes after 15 May 2027, according to the DNP.
Which months are the Similan Islands closed?
The DNP closes the park from 16 May to 14 October every year, which covers late May through mid-October.
Can you stay overnight on the Similan Islands?
No. Overnight stays on the islands have been banned since October 2018, and the DNP confirmed in August 2026 that the park is open for day trips and diving only.
Can you visit the Similan Islands from Phuket?
Yes. The DNP lists Patong Pier in Phuket, about 90 km away, as a gateway, though the main pier is Thap Lamu in Phang Nga, about 70 km from the islands.
Is Koh Tachai open for the 2026-27 season?
No. No reopening had been announced by 6 October 2026, after more than nine years of closure.
Last checked: 6 October 2026. Before you travel, check the park’s Facebook page or call the park office on +66 76 453 272 (number from the DNP park page).
