When to visit

Is May a good month in Thailand?

Updated 5 June 2026

Short answer

May is a decent month if you choose the right part of Thailand. The Andaman coast (Phuket, Krabi) enters its rainy season and is at its cheapest and wettest. The Gulf coast (Samui, Koh Tao) is in its dry stretch and genuinely good. Bangkok and the north are workable with afternoon storms. Prices across the board drop 30-40% from January. May rewards flexible travellers who are willing to adjust destinations based on weather.

May is where the Thai calendar's two-coast story starts mattering most. The answer to "is May good?" is entirely about where you're going.

The Andaman coast: low season begins

Phuket, Krabi, Phi Phi, and Koh Lanta enter their rainy season in May. Phuket averages around 200-230mm of rain in May, concentrated in afternoon and evening storms rather than all-day rain. The Similan Islands close in mid-May. West coast beaches can have rough days, and some dive operators reduce their schedules.

This is also when Andaman coast prices drop sharply. A Phuket hotel that was $200 in January can be $80-100 in May. If you're okay with the weather being unpredictable and building the trip around beach time in the mornings, spas and Old Town in the afternoons, May Phuket is a real value proposition.

The Gulf coast: its good season

Koh Samui, Koh Phangan, and Koh Tao are doing well in May. This is one of the best months for diving on Koh Tao: visibility builds toward 25-30m, whale sharks can still be around, and sea conditions are calm. Samui averages around 150-180mm of rain in May, mostly overnight, with reasonable daytime weather.

May is underrated for the Gulf islands. While everyone avoids Phuket because of the rain, Koh Tao and Samui are in their comfortable shoulder season: decent weather, lower prices than February, and significantly fewer tourists.

Bangkok

May is when the rainy season starts. Around 180-190mm over 14-15 days, with afternoon storms as the daily pattern. The BTS and MRT network keeps running regardless. Staying in Sukhumvit, Silom, or Ari means you're connected even when streets flood. Bangkok works in May if you're near rapid transit.

Chiang Mai and the north

The rains arrive in May and wash the smoke away. Air quality improves dramatically from the March-April burning season. By late May, the north is green, clear, and genuinely pleasant. The waterfalls at Doi Inthanon are starting to flow properly. May is when Chiang Mai goes from one of its worst months to one of its better ones.

Prices

The biggest monthly price drop of the year happens in May on the Andaman coast. Everywhere else follows with 20-35% reductions. For budget-conscious travellers, May opens up accommodation that simply isn't in range in January.

For the full May picture, see our Thailand in May guide.