Thailand has three seasons, and they do not arrive everywhere at once
The country runs on cool, hot and rainy — but the coasts are on different schedules to each other and to the interior, which is the single most useful planning fact nobody tells first-time visitors.
Cool season, November to February
Dry, clear and comfortable almost everywhere. This is peak season: best weather, highest prices, fullest hotels. The north is at its finest, the Andaman is open for business, and the whole country is pleasant. Book ahead for December and January.
Hot season, March to May
Genuinely hot — well into the thirties, humid, and draining by mid-afternoon. The north also gets the burning season in March and April, when agricultural smoke pushes air quality in Chiang Mai to some of the worst readings in the world. Avoid the north in those two months if you can. The islands are fine, and prices dip.
Rainy season, June to October
Misunderstood. Rain here usually means a heavy downpour in the late afternoon rather than all-day drizzle, and the country turns green: waterfalls run, rice fields fill, prices fall and crowds thin. The exceptions worth respecting are September and October on the Andaman, when the sea gets rough and some island boats stop.
The two-coast problem
The Andaman coast (Phuket, Krabi, Koh Lanta, the Similans) is at its best November to April. The Gulf coast (Samui, Phangan, Tao) is at its best February to September and takes its monsoon in October and November. If you are travelling in October, that difference decides your entire trip.
Timing your trip
- Best time to visit Thailand — month by month, coast by coast.
- Festival and public-holiday calendar — every 2026–27 date, with a downloadable .ics.
- Loy Krathong 2026 — 24 November, and where to be for it.
- Yi Peng 2026 — the Chiang Mai lantern festival, same nights.
- The Similan Islands — a park with a hard opening and closing date.
- Thai fruit by month — mangosteen, durian and longan all run to a calendar.
- Loei — the cool-season escape nobody warns you about.
The province matcher takes your month as an input and flags provinces that are wrong for it, rather than quietly hiding them.
When to visit Thailand: your questions, answered
What is the best month to visit Thailand?
For nationwide good weather, late November through February. December and January are the most reliable and the most expensive. If you want the Gulf islands specifically, February to September is a better window than the traditional peak.
Is it worth visiting Thailand in the rainy season?
Often, yes. Rain tends to come as a heavy late-afternoon burst rather than all day, the landscape is at its greenest, and both prices and crowds drop sharply. Avoid the Andaman coast in September and October, when the sea can stop the boats.
When is the burning season in Chiang Mai?
Roughly March and April, when agricultural burning pushes air quality in the north to among the worst in the world. If you are sensitive to air pollution, plan the north for November to February instead.
Which coast should I visit and when?
Andaman — Phuket, Krabi, Koh Lanta — from November to April. Gulf — Samui, Phangan, Tao — from February to September. They have opposite monsoons, so the month decides the coast rather than the other way round.