The month Thailand changes sides
May is the turning point of the Thai year. The south-west monsoon arrives over the Andaman Sea, and Phuket, Krabi and Koh Lanta begin their long wet season. But Thailand has two coasts on two different monsoon clocks, and the Gulf side — Ban Krut, Hua Hin, Chumphon, Koh Samui, Koh Tao — stays largely dry until the autumn.
That's the simple rule worth remembering for the whole European summer: from May onward, choose the Gulf. It's still hot — May sits at the end of Thailand's hottest stretch — but the crowds have gone, prices dip, and the first mangosteens and rambutans of the fruit season appear on roadside stalls.
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At a glance
Thailand in May
- Andaman monsoon begins — Phuket and Krabi turn wet
- Gulf coast stays mostly dry: Ban Krut, Hua Hin, Samui
- Hot: 32–35°C, the tail end of Thailand's hottest stretch
- Fruit season starts — mangosteen, rambutan and durian
Good to know
Good to know
- From May onward, the rule of thumb is simple: choose the Gulf coast over the Andaman coast.
- May opens the fruit season — buy mangosteen and rambutan by the kilo from roadside stalls.
- Book rooms with a pool: May afternoons are hot, and green-season rates make upgrades cheap.
- Evening thunderstorms pass quickly — plan beach time for mornings and long lunches for the odd downpour.
