Why this guide: about 9,900 people a month search Google for “best time to visit thailand” (US, DataForSEO Labs, September 2026). This is the answer we would give a client, written to be booked from.
The short answer
- Best overallNovember–February (cool and dry nationwide)
- CheapestMay–June and September–October on the Andaman coast
- AvoidApril for heat (unless you want Songkran); September for the wettest Andaman weather; October–November for the Gulf islands
Cool season (November–February)
Bangkok drops to 30°C with low humidity, Chiang Mai's mornings are 15°C and the whole country is dry. Loy Krathong (November full moon) fills the rivers with candle rafts and the Chiang Mai sky with lanterns. This is peak season: Phuket, Krabi and Koh Samui hotels are at full rate, and Christmas–New Year is the single most expensive fortnight.
Hot season (March–May)
Temperatures climb to 35–40°C; the north is hazy from agricultural burning in March–April. Songkran, the Thai New Year, turns 13–15 April into a nationwide water fight — the best week of the year if you want it, the worst if you don't. The beaches are still dry until May and prices soften after Songkran.
Two monsoons, two coasts
The south-west monsoon brings rain to the Andaman coast — Phuket, Krabi, Khao Lak, the Phi Phi islands — from May to October, heaviest in September; some beaches close to swimming and the Similan Islands park shuts (mid-May to mid-October). The Gulf coast — Koh Samui, Koh Phangan, Koh Tao — has its own, later wet season from October to December. So: Gulf islands in July–August, Andaman in December–March, and you have year-round sun.
Green-season value
May–June and September–October bring 30–50% discounts at Phuket and Krabi resorts, sunny mornings and short afternoon downpours; it is a good bet if you pick a resort with a pool and are flexible about beach days. Bangkok is busy and reasonable all year; the cool season premium there is modest.
Booking from the engine
Bangkok Suvarnabhumi (BKK) is the international hub; Phuket (HKT) and Samui (USM) have direct regional flights. Use the Bangkok destination page for the city stay, the flights tab for the domestic hop, and a chauffeur for the BKK arrival — the taxi queue at 1 a.m. is not the Thailand you came for.
Three things to get right
- Gulf islands in summer, Andaman in winter — there is always a dry coast.
- Loy Krathong in Chiang Mai is the most beautiful night of the year.
- Green season on Phuket: mornings are sunny; book a pool.
Book it
Featured destination: Bangkok — hotels, airport and activities on one engine page.
