Thailand for couples: which islands and national parks close, and when

Updated 8th Sep 2026

Several of the islands and marine parks a couple would plan a trip around close for months at a time, on dates the parks publish in advance. The parks on the Andaman side and the marine park off Koh Samui do not close in the same months, so which coast you pick changes which months are open. Below are the published dates, park by park, and the rules that apply once you are there.

Which parks are open when

Several of the Andaman parks close for the middle of the year. Mu Ko Similan and Mu Ko Surin, both in Phang Nga, are two of them, and their own park pages give 1 November as the start of the open season.

Mu Ko Ang Thong, the marine park off Koh Samui in the Gulf, runs the other way. It closes in November, and on the National Park Office's list into the first half of December. Those are the months when Mu Ko Similan and Mu Ko Surin have just reopened.

None of that is a view on the weather across the country. That is a separate question, and it has its own guide to the best time to visit Thailand.

The closure dates published for the same park differ between the National Park Office's list and the Department of National Parks' own page for that park, in some cases by more than a fortnight. Check the dates with the park itself before booking anything that depends on them.

Published closure dates, both sources side by side

Two sources publish these dates: the National Park Office's list, which the Tourism Authority of Thailand (TAT) links from its note on national park openings and closures, and the Department of National Parks' own page for each park. Where the two differ, both are given.

Park	National Park Office list	The park's own page
Mu Ko Similan	Ko Similan and Ko Miang, 16 May to 14 October	Closed 16 May to 31 October
Mu Ko Surin	All tourist sites and accommodation, 16 May to 14 October	Closed 1 May to 31 October
Mu Ko Ang Thong	Tourist sites and accommodation, 1 November to 15 December	Closed 1 to 30 November
Mu Ko Lanta	Ko Rok, 1 June to 30 September. Ko Ha with Hin Daeng and Hin Muang, 1 August to 30 September	Ko Rok, Hin Daeng - Hin Muang and Ko Ha, closed 16 May to 31 October
Hat Noppharat Thara - Mu Ko Phi Phi	Ao Maya, Ao Losama and Ao Loko, 1 August to 30 September. Ko Yung closed with no end date. Diving at the west of Ko Kai closed from 16 May onwards	No closed season given
Phu Kradueng	Summit tourist sites, accommodation zone 1 and Wang Kwang campsite, 1 June to 30 September	Summit only, closed 1 June to 30 September

The Andaman parks

Mu Ko Surin's own page gives the reason for its closure. In the rainy season the southwest monsoon brings heavy rain and strong waves, which makes travel to the park unsafe for visitors. Its rainy season runs from mid-May to October, with over 3,000 mm of rain a year.

Mu Ko Similan carries a second closure with no end date on it. Fantasy Reef, Eel Garden, Anita's Reef, East of Eden, Ko Ngang Chang and Ko Tachai are listed as closed with no reopening date given, so a diving itinerary built around a named site there can be out of date before you arrive.

In Mu Ko Lanta the closures do not cover the whole park. The National Park Office's list gives two separate windows, one for Ko Rok and another for Ko Ha with Hin Daeng and Hin Muang, while the park's own page gives a single window covering all three. Neither closure names the main island of Koh Lanta.

Ao Phang Nga closes Ko Lawa Yai, Ao Khian and Ko Boi Yai, along with one accommodation zone and a campsite, from 1 August to 30 September.

The National Park Office's list closes Ao Maya, Ao Losama and Ao Loko, in Hat Noppharat Thara - Mu Ko Phi Phi, from 1 August to 30 September every year, and lists no annual closure for the rest of the park that covers the Phi Phi islands. Two further closures sit under the same park with no reopening date given: Ko Yung, and diving off the west side of Ko Kai, closed from 16 May onwards. The park's own page gives no closed season at all, and puts average rainfall at about 2,231 mm a year, with July the wettest month and February the driest.

Krabi is the gateway for both Phi Phi and Ko Lanta. The route page for Bangkok to Krabi carries the schedule for that leg.

The Gulf and Mu Ko Ang Thong

Mu Ko Ang Thong is the marine park reached from Koh Samui, and its closed months fall inside the open season Mu Ko Similan and Mu Ko Surin publish. The National Park Office's list gives 1 November to 15 December. The park's own page gives 1 to 30 November.

That page sets out three seasons: hot from February to mid-May, rainy from May to mid-October under the southwest monsoon, and cool from October to February under the northeast monsoon. Average rainfall is about 2,000 mm a year. Koh Samui is the gateway for the park, and the Bangkok to Koh Samui route page carries that leg.

Khao Sok and Phu Kradueng

Khao Sok is in Surat Thani province, and its own park page names December to April as the period to visit. Rain there begins in late April and runs to late December, heaviest from May to November, and the page puts the annual total at 1,636 mm.

Two sites inside Khao Sok close on dates of their own: the Bua Phut site at km 111, from 1 April to 30 November, and Tham Nam Thalu, from 1 June to 30 November. Both reopen in December, inside the period the park page recommends. Two more, Namtok Sip Ed Chan and the Bua Phut site at the Bang Man ranger station, are closed with no reopening date given.

Phu Kradueng, in Loei, closes its summit from 1 June to 30 September, and the two sources agree on those dates. The list names the summit tourist sites, accommodation zone 1 and the Wang Kwang campsite, and the park's own page states that the closure applies only on the summit. The summit is out for anything planned in those months.

Ko Chang

Three islands in Mu Ko Chang, in Trat, are closed with no reopening date given: Ko Thong Lang, Ko Kra and Ko Thian. A dive site at Ko Yak Yai is listed as closed to scuba diving from 11 November onwards. Neither source gives an annual closed season for the park as a whole.

The park's own page puts average rainfall at about 4,700 mm a year, the highest figure of any park named on this page.

Park rules, drones and beaches

Sunscreen containing any of four chemicals may not be brought into or used in a national park, under an announcement published in the Government Gazette on 3 August 2021. The four are oxybenzone (benzophenone-3), octinoxate (ethylhexyl methoxycinnamate), 4-methylbenzylidene camphor (4MBC) and butylparaben. Check the ingredients before you pack.

Foam food containers and a list of single-use plastics are banned in a national park as well, under an announcement published in the Government Gazette on 5 April 2022. It covers foam food containers, plastic carrier bags thinner than 36 microns, plastic food boxes, thin single-use plastic cups, plastic straws, and plastic spoons and forks. Bringing them in is an offence under section 20 with section 47 of the National Parks Act B.E. 2562 (2019) and carries a fine.

A drone needs two separate registrations before it flies. The National Broadcasting and Telecommunications Commission (NBTC) registers ownership and the radio frequency, and the Civil Aviation Authority of Thailand (CAAT) registers the aircraft and the pilot. Registration with a single agency is not enough.

NBTC registration applies to every drone whatever its weight. CAAT registration applies as well to any drone with a camera, any drone over 2 kg and under 25 kg, and all drones over 25 kg. Registration is not the last step: flight details have to be submitted to CAAT through its UAS Portal at least three days before each flight, and the Anti-Drone Centre notified before each approved flight.

Flying is permitted only in daylight, in clear weather and within visual line of sight, not into or near cloud, and not within nine kilometres of an airport or a temporary airfield. Safe distances are 30 m for drones under 2 kg and 50 m for drones of 2 to 25 kg, and third-party liability insurance is required.

Flights over urban areas or gatherings, and near government buildings, hospitals, military zones or restricted areas, are prohibited unless authorised. National parks are not named in that list, but TAT tells visitors to check a park's own requirements before flying, so an aerial shot of a park is a question for the park itself. TAT publishes an updated drone guide for tourists.

Smoking on Thai beaches was banned with effect from November 2017, according to TAT. Park rules and animal attractions are the subject of the guide to ethical travel in Thailand.

Frequently asked questions

Which months are Mu Ko Similan and Mu Ko Surin closed?

Both close for the middle of the year. The National Park Office's list gives 16 May to 14 October for each of them, while the Department of National Parks' page for Mu Ko Similan gives 16 May to 31 October and its page for Mu Ko Surin gives 1 May to 31 October. Check with the park before booking dates near either end of those windows.

When does the marine park off Koh Samui close?

Mu Ko Ang Thong closes 1 November to 15 December on the National Park Office's list, and 1 to 30 November on the Department of National Parks' own page. Those months sit inside the open season Mu Ko Similan and Mu Ko Surin publish, so the two coasts suit different dates.

Is Ko Phi Phi affected by a national park closure?

Yes, in part. The National Park Office's list closes Ao Maya, Ao Losama and Ao Loko from 1 August to 30 September each year, and gives no annual closure for the rest of Hat Noppharat Thara - Mu Ko Phi Phi; the park's own page gives no closed season. Ko Yung, one of the islands inside that park, is closed with no reopening date given, and diving off the west side of Ko Kai is closed from 16 May onwards.

Can I fly a drone over a national park in Thailand?

Not without approval. A drone has to be registered with both the National Broadcasting and Telecommunications Commission and the Civil Aviation Authority of Thailand before it flies at all, and flight details have to be submitted to the aviation authority at least three days before each flight. TAT also tells visitors to check a national park's own requirements before flying.

Which sunscreen chemicals are banned in Thailand's national parks?

Oxybenzone (benzophenone-3), octinoxate (ethylhexyl methoxycinnamate), 4-methylbenzylidene camphor (4MBC) and butylparaben. A 2021 announcement in the Government Gazette bans bringing or using sunscreen containing any of the four inside a national park.