Thai Islands, Thailand
"Longtail boats, limestone cliffs, and beaches for every mood"
Thai Islands at a glance
- Best time to go
- Thailand's two coasts run on different calendars. The Andaman coast (Phuket, Krabi, Phi Phi) is best roughly November to April, and the Gulf coast (Koh Samui, Koh Phangan, Koh Tao) is best roughly December to September, with its wettest stretch usually October to December. If you're set on one specific island, check its coast's pattern rather than assuming a single Thailand-wide season.
- How long to stay
- We'd suggest seven to ten days to properly enjoy two or three islands, or an easy five to seven days on just one.
- Who it's for
- Beach-lovers, divers and island-hoppers who want a mix of party islands, quiet bays and diving in one region.
- Might not be for you if
- You're chasing calm seas on both coasts at once. Because they run on opposite patterns for part of the year, a trip spanning both coasts means accepting rougher conditions on one of them.
Thailand's islands split neatly into two seas and two moods. The Andaman side — Phuket, Krabi, Koh Lanta, Koh Phi Phi — is all vertical limestone and turquoise water. The Gulf side — Koh Samui, Koh Phangan, Koh Tao — is gentler, greener and cheaper to dive. Pick one sea per trip and let the monsoon calendar decide which.
Best Time to Visit
November to April for the Andaman; January to August for the Gulf
Nov – Feb
Peak season on the Andaman: calm seas, clear skies, highest prices.
Mar – May
Hot and still. Great visibility for diving, quieter beaches after Songkran.
Jun – Aug
Andaman monsoon, but the Gulf islands are at their driest and sunniest.
Sep – Oct
Wettest across both coasts. Bargain prices and dramatic skies if you don't mind rain.
Getting Around
Fly into Phuket, Krabi or Samui, then move by ferry and longtail. Distances are short but timetables are seasonal.
⛴️ Ferries
Daily connections between all the major islands; reduced in low season.
🛶 Longtail Boats
Charter by the hour for beaches with no road access, like Railay or Bamboo Island.
🛵 Scooters
The way to explore Lanta, Samui and Phangan. Helmet on — police checkpoints are routine.
🚐 Minivan + Boat Combos
Sold as one ticket from most towns; slow but simple and cheap.
💡 Book the first ferry of the day — afternoon crossings get choppy and cancellations cascade.
Suggested Itineraries
Arrive Krabi
Settle in Ao Nang, first seafood dinner on the beach road.
Railay Day
Rock climbing intro or a lagoon scramble, then Phra Nang sunset.
Ferry to Koh Lanta
Afternoon on Long Beach, sunset bar with your feet in the sand.
Lanta by Scooter
Old Town, Mu Ko Lanta National Park lighthouse, quiet southern beaches.
Four Islands from Lanta
Koh Rok or Koh Haa snorkelling — some of the clearest water in the country.
Phi Phi Stop
Ferry via Phi Phi, viewpoint hike at dawn, Maya Bay by boat.
Phuket & Departure
Ferry to Phuket, last swim, evening flight.
✨ Feeling dizzy already? Breathe. This is a menu, not a to-do list — skip a stop, nap by a fountain, leave a couple of sparks for next time.
Highlights
Must See
- Railay Beach
- Koh Lanta
- Ang Thong Marine Park
- Koh Tao dive sites
Local Cuisine
Insider Tip
The two coasts have opposite monsoons — if the Andaman is stormy in October, cross to the Gulf and the sun follows you.
Thai Islands travel questions, answered
When is the best time to visit the Thailand islands?
It depends on the coast. The Andaman side (Phuket, Krabi, Phi Phi) is best roughly November to April, in its dry season. The Gulf side (Koh Samui, Koh Phangan, Koh Tao) has a different pattern and is generally good roughly December to September, with its wettest weather usually October to December, the opposite of what you might expect.
Which Thailand islands are best for diving?
Koh Tao on the Gulf coast is one of the country's most popular and affordable dive-training hubs, generally good outside its own wetter months. The Similan Islands, off the Andaman coast, are known for excellent visibility but are typically only accessible roughly mid-October to mid-May, when the national park is open and seas are calm enough for boats.
Do boat trips get cancelled in bad weather?
Yes, when conditions warrant it. Speedboat and ferry operators commonly postpone or cancel trips when swells reach a certain height, particularly during each coast's wetter months, so build a buffer day into your itinerary if you have a specific island crossing that matters.
How many days do you need for the Thailand islands?
Seven to ten days lets you properly enjoy two or three islands with some downtime between them. If you only have five to seven days, focusing on just one island and a couple of day trips tends to work better than rushing between several.
Details last checked 23 September 2026.