Is May a bad time for Thailand?

May marks the start of the southwest monsoon on the Andaman Coast (Phuket, Krabi, Koh Phi Phi) — expect heavy afternoon showers but not constant rain. The Gulf Coast (Koh Samui, Koh Phangan) remains dry and excellent. Prices drop from April, making May good value.

Does it rain all day in Thailand in May?

No — monsoon rain in Thailand typically falls as heavy afternoon showers, not all-day downpours. Mornings are usually clear. This pattern allows for activities in the morning and afternoon shelter during rain. The north experiences some rain but not as heavy as the south.

Which Thai islands are best in May?

The Gulf Coast islands (Koh Samui, Koh Phangan, Koh Tao) are the best choice in May — they are in dry season while the Andaman Coast gets its monsoon rains. Koh Samui in May has calm, clear seas and lower prices.

Thailand in May | The Thailand Guides

Thailand in May: Weather, Crowds and What to Expect

10 May 2026 · 1 min read Practical

Thailand’s geography creates distinct regional weather patterns — the Andaman Coast (Phuket, Krabi, Koh Phi Phi) and Gulf Coast (Koh Samui, Koh Phangan) have opposite monsoon seasons. Understanding which applies to your destination in May is the key planning question.

Weather in May

Monsoon arrives on the Andaman Coast; Gulf Coast stays dry. Prices drop significantly. Good for budget travel and for those happy with afternoon showers on the Andaman side.

Where to Go in Thailand in May

Bangkok: Bangkok city guide
Chiang Mai: Chiang Mai guide
Phuket: Phuket guide
Koh Samui: Koh Samui guide
Koh Phangan: Koh Phangan guide
Krabi: Krabi guide

Planning

See the best time to visit Thailand for a full seasonal comparison, or the Thailand budget guide for cost planning.

Frequently Asked Questions

Is May a bad time for Thailand?: May marks the start of the southwest monsoon on the Andaman Coast (Phuket, Krabi, Koh Phi Phi) — expect heavy afternoon showers but not constant rain. The Gulf Coast (Koh Samui, Koh Phangan) remains dry and excellent. Prices drop from April, making May good value.
Does it rain all day in Thailand in May?: No — monsoon rain in Thailand typically falls as heavy afternoon showers, not all-day downpours. Mornings are usually clear. This pattern allows for activities in the morning and afternoon shelter during rain. The north experiences some rain but not as heavy as the south.
Which Thai islands are best in May?: The Gulf Coast islands (Koh Samui, Koh Phangan, Koh Tao) are the best choice in May — they are in dry season while the Andaman Coast gets its monsoon rains. Koh Samui in May has calm, clear seas and lower prices.