Similan and Surin islands reopen on 15 October

The single most useful piece of Thailand travel news for anyone building a November or December trip has nothing to do with visas or flight prices. It is a date: 15 October 2026. That is the day the Andaman Sea's marine national parks come out of their annual monsoon closure, and the day the best half of Thailand's island year quietly begins.

Two parks matter most. Mu Ko Similan and Mu Ko Surin, both in Phang Nga province, have been shut to visitors and to overnight stays since 15 May under an order from the Department of National Parks, Wildlife and Plant Conservation — five months, to the day. Officials have spent the closure repairing piers, moorings and water systems, and letting the reefs sit undisturbed. From mid-October the boats start running again.

What actually reopens on 15 October 2026

The closure order covers both tourism and overnight accommodation at Mu Ko Surin National Park and Mu Ko Similan National Park. Surasak Anuson, director of Protected Area Regional Office 5, framed it as two things at once: a safety measure while the Andaman is under southwest monsoon swell, and a recovery window for the ecosystem before the high season crowds arrive.

Those crowds are substantial. The Similan Islands alone drew more than 400,000 visitors in the last full season and generated over 215 million baht in park revenue, up from 197 million the year before. More than ninety per cent of those visitors were foreign. Park chief Siriwat Suebsai has been blunt that the daily caps, the mooring rules and the closure itself are what keep the place worth visiting at all. It is the rare piece of Thailand travel news where the restriction is the selling point.

In practice, mid-October is the park's official opening; the commercial season builds behind it. Day-trip speedboats from Khao Lak generally start within days of the gate opening. Liveaboards, which need settled seas for multi-night itineraries, mostly begin in November. If you are planning the dive trip of a lifetime, aim for late November to April. If you simply want the beaches with fewer people on them, the second half of October is the sweet spot.

Mu Ko Similan: nine islands, one very strict rulebook

The Similans are nine granite islands about 70 km offshore, and they look nothing like the limestone scenery most visitors associate with Thailand islands. Rounded boulders the size of houses sit on flour-white sand; the water offshore drops into visibility that regularly exceeds 25 metres. The famous viewpoint on Ko Similan (island 8), reached by a short scramble over those boulders, is the photograph everyone comes for.

Entry is 500 baht for adult foreign visitors and 250 baht for children aged 3–14, collected on arrival and valid for the day. Thai nationals pay 100 and 50 baht. Visiting hours run roughly 08:00 to 16:00, and you cannot land before or linger after. Overnight camping and park bungalows on Ko Miang (island 4) reopen with the park, but they sell out early and are booked through the DNP reservation system rather than through tour agents.

Mu Ko Surin: reefs, Moken villages and Thai culture

Surin is the quieter, wilder half of the pair, 60 km off the coast near Khuraburi and only a few kilometres from the Myanmar maritime border. It has the better shallow snorkelling of the two — huge, healthy hard-coral gardens you can float over in two metres of water — and it is far less trafficked. For divers and snorkellers it is consistently ranked among the best places to visit in Thailand, and it stays that way largely because getting there takes effort.

Fees match the Similans at 500 baht for adults and 250 baht for children. Opening hours are 08:30 to 16:30 across the 15 October to 15 May season. Surin is also home to a Moken sea-nomad village at Ao Bon, and visits there are one of the more genuinely affecting encounters with Thai culture available on any Thailand beach trip — provided you go with a guide who treats it as a community, not a photo stop.

Getting there: piers, times and the real cost of the trip

This is the part that catches people out, because almost nobody sleeps at the departure point by accident. If you travel to Thailand with the Similans on your list, plan the logistics before the flights.

• For the Similans — boats leave from Thap Lamu pier, about 20 minutes south of Khao Lak town and roughly 2 to 2.5 hours by road from Phuket airport. The speedboat crossing takes 1 to 1.5 hours.
• For Surin — departures are from Khuraburi pier, a further 90 minutes north; the crossing is around an hour.
• Day-trip pricing — expect roughly 2,500–4,000 baht per person from Khao Lak including transfers, lunch and snorkel gear, with the 500 baht park fee usually charged separately on arrival. Phuket pickups add 500–1,000 baht and a 05:30 alarm.
• Liveaboards — four-day, four-night Similan and Surin trips typically run from around 30,000 baht, with most operators restarting in November.
• Sleeping close — Khao Lak is the practical base for both parks and is far cheaper than Phuket. Bang Niang and Nang Thong beaches have the best mix of guesthouses and restaurants.

Where the Andaman fits in a wider Thailand itinerary

Mid-October is an awkward, wonderful moment in any Thailand itinerary. The northeast monsoon has not yet fully arrived on the Gulf side, the Andaman is drying out, and the crowds are three weeks behind you. A fortnight that starts in Bangkok, spends four nights in Khao Lak for the parks, then drifts south into Krabi and out to Koh Phi Phi is close to the ideal shape for a first trip — and it lines up with Maya Bay coming back into season on 1 October.

If you would rather stay put, the mainland side of Phang Nga has enough for a week on its own: the bay itself, Khao Sok's rainforest and lake, and a coastline that stays quiet long after Phuket fills up. For general Thailand vacation planning, treat 15 October as the moment the southern half of the country flips from shoulder season to high season — hotel rates on the Andaman coast start climbing within a fortnight of it.

Practical tips for Thailand vacation planning

• Book the park fee into your budget. Tour prices quoted online often exclude the 500 baht entry, and it is cash on arrival at the pier or the island.
• Take the first boat. Departures around 08:00 reach the Similans before the mid-morning convoy; the viewpoint is genuinely peaceful for about forty minutes.
• Reef-safe sunscreen only. Oxybenzone-based sunscreens are banned in Thai marine national parks and rangers do check.
• No single-use plastic. Bottles, foam boxes and plastic bags are refused at the gate. Bring a refillable bottle.
• Sea sickness is real. The October crossing can still be lumpy. Take something an hour before boarding rather than on the boat.
• Check the date before you commit. The department confirms the exact opening a week or two ahead, and weather has pushed it by a day or two in past years. Follow the Thailand travel news in the fortnight before you fly.

That caveat aside, this is the piece of Thailand travel news worth putting in the calendar. The Andaman spends five months closed for a reason, and the fortnight after it reopens is the closest most visitors will get to seeing these islands the way the closure leaves them.