Thailand Islands Guide: Seasons, Ferries and Park Fees
The southwest monsoon covers Thailand from mid-May to mid-October, the northeast monsoon runs to mid-February, and heavy rain lasts in the south until December. Similan and Surin close from 16 May to 14 October. Phi Phi charges foreign adults THB 400.
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Season split: Gulf and Andaman by month
Thailand has two sea coasts, and the rain arrives on them at different times. The Andaman Sea is on the west side of southern Thailand and the Gulf of Thailand on the east side. The west coast of the south is Ranong, Phang Nga, Phuket, Krabi, Trang and Satun. The east coast includes Chumphon and Surat Thani.
| Period | What happens | Islands affected |
|---|---|---|
| Mid-May to mid-October | Southwest monsoon with heavy cloud and rain, especially along the coasts | Similan and Surin closed 16 May to 14 October |
| 1 June to 30 September | National park closures on listed sites | Koh Rok, Adang and Rawi |
| 1 August to 30 September | Maya Bay, Loh Samah and Lo Ko bay closed | Phi Phi |
| Mid-October to mid-February | Northeast monsoon | Heavy rain continues in the south until December, with more on the east side |
| 1 November to 15 December | Ang Thong park lists closures | Gulf, near Samui |
The monsoon dates are not fixed: the start of the rainy season can come 1 to 2 weeks early or late. Opening of some sites can change with the weather. The Best Thai islands by month guide holds the full closure list.
How to reach each island
Match the island to the cheapest published way to get there. The table gives the main fares in this site’s guides.
| Island | How to get there | Published fare |
|---|---|---|
| Phuket | Smart Bus from the airport | Flat THB 100 |
| Samui | Bangkok Airways direct; or fly to Surat Thani and take a ferry | From THB 2,752; THB 1,110 plus THB 550 |
| Koh Phangan | Lomprayah from Samui; Raja from Donsak | THB 350 catamaran, THB 250 ferry; THB 270 |
| Koh Tao | Lomprayah catamaran from Samui, 08:00 to 09:30 | THB 700 |
| Phi Phi | Andaman Wave Master from Krabi, 2 hours | THB 450 |
| Krabi | Direct flights from Bangkok | THB 1,110 to THB 1,224 |
For Samui, the Raja crossing between Donsak and Lipa Noi takes about 1 hour 30 minutes, with the first sailing at 05:00. Raja charges THB 200 for an adult to Samui. See Surat Thani to Koh Samui, the Samui, Phangan and Tao ferries, Bangkok to Koh Samui and Bangkok to Krabi.
Krabi to Phi Phi leaves daily at 09:00. You can buy a ticket at the pier, but the operator recommends booking ahead in high season. The Phi Phi ferry from Tonsai Pier back to Krabi leaves at 10:30. The full route is in Krabi to Koh Phi Phi by ferry.
National park fees and closures
Entry fees depend on the park’s group. Under the 2022 schedule a Group 2 park charges a foreign adult THB 200 and a foreign child THB 100. Group 3 charges THB 300 and THB 150, and Group 4 charges THB 500 and THB 250.
The Phi Phi islands add a special charge. At Ko Phi Phi Don, Ko Phi Phi Le and Ko Mai Phai a foreign adult pays THB 400 and a foreign child THB 200. Mu Ko Ang Thong National Park, in the Gulf, is a Group 2 park. A DNP notice dated 19 September 2022 also sets special service charges for tourist sites in five national parks.
The Similan Islands close for the season from 16 May to 14 October every year. The Similan park opened for the 2026 season on 15 October. Park e-tickets are piloted in six parks, including Similan and Phi Phi.
The e-ticket takes debit cards, credit cards, cross-bank bill payment and PromptPay.
See Thailand national park fees and Maya Bay and the Phi Phi park fee. Maya Bay lies on Phi Phi Le. It is closed from 1 August to 30 September in the 2026 closure announcement, and swimming is banned there.
Gulf islands: Samui, Phangan and Tao
Samui, Phangan and Tao sit on the east side of the south, where heavy rain continues until December. Bangkok Airways advertises Samui flights from THB 2,500. The Koh Samui guide covers the island by area.
Koh Tao is the diving island. A PADI Open Water course costs THB 9,900 at Isla Tortuga Divers and THB 12,000 at Siam Scuba. Anyone aged 10 or older can learn to dive with PADI. A certified diver may dive up to 18 m anywhere in the world.
February to May are the best months on Koh Tao: calm seas, 20 to 30 m of visibility and steady weather. The diving emergency chamber phone is +66 81 081 9777. Read the Koh Tao diving guide before you book.
Andaman islands: Phuket, Krabi and Phi Phi
Phuket’s areas differ.
Patong is the largest and most popular beach resort and is known for nightlife. Kata is a busy, clean tourist beach with good surf. Karon is the second most developed beach after Patong. Phuket Town has the cheapest accommodation.
A counter taxi from the airport to Patong has a fixed price of THB 800, while the Smart Bus costs THB 100. The Phuket guide has the rest, and phuketanchor.com (opens in a new tab) covers Phuket in depth.
In Krabi, Ao Nang is the busiest beach in high season, roughly 1 November to 30 April. Railay is on the tip of a peninsula blocked by Khao Nang Mountain, so access is only by boat. The rainy season runs from mid-May to mid-October. See the Krabi and Ao Nang guide.
Phi Phi is best from November to April, when the weather is more temperate and the rains less frequent. The Koh Phi Phi guide compares the ferry and the speedboat.
Pattaya and Hua Hin
Two beach towns on the Gulf coast near Bangkok work without a long ferry. In Pattaya, the Sanctuary of Truth day tour costs 500 baht for adults. The Pattaya to Koh Larn ferry fare rose from 30 baht to a single fare of 40 baht per person from 10 April 2026. In upper Thailand the most rain falls in August or September.
Near Hua Hin, a Group 2 park charges a foreign adult THB 200, and Kaeng Krachan, a Group 3 park, charges THB 300. See the Pattaya guide and the Hua Hin guide.
Beach rules and safety
Smoking is banned on listed beaches. Nobody may smoke or drop cigarette butts there, except in an area officials have provided. The list opens with six beaches on the eastern Gulf coast, and later names Hua Hin, Cha-am and Bo Phut on Koh Samui.
It ends with Patong and Khao Lak. Breaking the order carries up to 1 year in prison, a fine of up to THB 100,000, or both. See the beach smoking ban guide.
Thailand has lifeguards on duty at designated beaches and a flag system; follow warning signs, especially red flags.
Two red flags mean very dangerous and no swimming at all. In the monsoon, strong waves make swimming impossible, or possible only in designated areas. For a jellyfish sting, call 1669 and pour household vinegar for at least 30 seconds. The jellyfish and rip current guide has the first-aid steps.
Nobody may sell alcohol outside 11:00 to 24:00. Hotels and airport terminals serving international flights are exempt, and entertainment venues sell within their licence hours. See Thai alcohol hours and fines.
Common mistakes
- Booking Similan or Surin between 16 May and 14 October, when both are closed.
- Planning Maya Bay between 1 August and 30 September.
- Assuming Gulf islands are dry in November: heavy rain continues in the south until December.
- Forgetting the THB 400 Phi Phi special charge on top of the ferry.
- Washing a jellyfish sting with fresh water.
Common questions
Which Thai islands are best in which month?
The southwest monsoon runs from mid-May to mid-October. Heavy rain continues in the south until December, and the east side gets more rain than the west. November to April is the best time for Phi Phi.
When are the Similan Islands open?
The Similan Islands close for the season from 16 May to 14 October every year.
How much is the ferry from Krabi to Koh Phi Phi?
The Andaman Wave Master ferry costs THB 450 for adults and takes 2 hours. A speedboat takes about 1 hour at THB 450 to 500 a seat.
How do I get to Koh Phangan and Koh Tao?
From Samui, a Lomprayah catamaran to Phangan costs THB 350 and to Koh Tao THB 700. From Donsak, Raja Ferry charges THB 270 to Phangan.
How much is the national park fee at Phi Phi and Maya Bay?
At Ko Phi Phi Don, Ko Phi Phi Le and Ko Mai Phai a foreign adult pays a special charge of THB 400 and a foreign child THB 200. Maya Bay lies on Phi Phi Le.
When is Maya Bay closed?
Maya Bay, Loh Samah bay and Lo Ko bay are closed from 1 August to 30 September in the 2026 closure announcement. Swimming at Maya Bay is banned under the reopening rules.
Can I smoke on a Thai beach?
No, on the listed beaches, except in areas officials provide. Breaking the order carries up to 1 year in prison, a fine of up to THB 100,000, or both.
What do I do after a jellyfish sting?
Get out of the sea, call for help and phone 1669. Pour household vinegar over the contact area continuously for at least 30 seconds. Never use fresh water, alcohol or rubbing.
Read next
Prices, timetables and opening hours change; check with the operator before you travel. See how guides are checked.
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