Journal · Destinations
Thailand: Andaman or Gulf
Thailand has two seas, and they take turns. When the Andaman coast — Phuket, Krabi, the limestone karsts of every postcard — is at its glassy best, the Gulf runs variable; when the monsoon shuts the Andaman down, the Gulf is open, warm and half-empty. Choosing the wrong one for your dates is the most common Thailand mistake, and it’s entirely avoidable once you know the rhythm.
The Andaman
The Andaman Sea sits on Thailand’s western coast — Phuket, Krabi, Koh Lanta, the Phi Phi Islands. It is the version of Thailand that produced the canonical beach photographs: the limestone karsts rising from calm water, the long-tail boats, the emerald colour that the photographs don’t exaggerate. The Andaman’s prime season is November through April. By May, the southwest monsoon arrives and the sea develops the swell that makes the crossings unpleasant and some of the beaches unswimmable. June through October, the Andaman is the destination to reconsider.
The Gulf
The Gulf of Thailand sits on the east coast — Koh Samui, Koh Phangan, Koh Tao. Its monsoon schedule is offset: the southwest monsoon that hits the Andaman coast in May affects the Gulf coast differently, because the mountains of the peninsula provide a partial buffer. The Gulf’s weather is more variable year-round, but it avoids the Andaman’s worst months. In July and August, when the Andaman is at its least reliable, the Gulf coast is typically swimmable.
“In July and August, when the Andaman is closed, the Gulf is open. Few people know this.”
The practical guide
If your dates are November through April, the Andaman is the choice. The Phi Phi Islands in February are the reason “beautiful” exists as an adjective. If your dates are June through September, the Gulf is the choice. Koh Samui in July is quiet — the European summer crowd goes to the Mediterranean — and the properties there, particularly the villa resorts on the north and west coasts, are genuinely excellent with rates 25 to 30 percent below peak.
Phuket vs. the islands
Phuket is a large island with a significant infrastructure — airports, roads, the full range of accommodation from backpacker to ultra-luxury. It is not the beach destination; it is the base for the beach destination. The beaches in Phuket proper are variable: Kata and Karon are adequate; the north coast has some quieter options. The Phi Phi Islands and Koh Yao Noi (quieter, between Phuket and Krabi) are the reason to be in the Andaman. The itinerary that lands in Phuket and then uses it as a base for boat trips outperforms the one that stays in Phuket and never leaves.
Match the coast to your calendar, not your wishlist, and Thailand delivers the postcard every time. Get it backwards and you’ll spend the week watching the weather. The sea you want is always open somewhere — it’s only ever a question of which one, when.