when is monsoon season in thailand

Monsoon (rainy) season in Thailand typically runs from about May/June through October, with the heaviest, most reliable rains between July and October.

Overall monsoon pattern

• Most of Thailand’s rainy or monsoon season is considered July–October, when the bulk of annual rainfall arrives.

• Showers often come as intense bursts that last a few hours rather than all‑day drizzle, especially earlier in the season.

• The southwest monsoon usually starts building not long after April (around and after Thai New Year/Songkran), then strengthens into full rainy season.

Regional differences

• Bangkok & central Thailand: Rains usually start in June or early July, peak around September, then ease off in October.

• North & northeast (e.g., Chiang Mai): Rainy period is roughly May–October, with most rain in August and September.

• Andaman coast (Phuket, Krabi) : West coast gets its wettest weather from about May to October due to the southwest monsoon.

• Gulf islands (Koh Samui side) : Pattern is shifted; this area is often drier June–September and can see heavier rain later in the year (around September–December).

If you’re planning a trip

• For drier, sunnier beach conditions in most regions, November–February is often described as the best window after the monsoon eases.

• Traveling in monsoon season can mean fewer crowds and greener scenery, but you should expect possible transport delays, rough seas, and short‑notice plan changes.

Information gathered from public forums or data available on the internet and portrayed here.