The rainy season does not mean rain throughout your trip, but timing and intensity vary each day. Leave time for meals and indoor breaks between outdoor activities, and check wind and waves as well as rain for coastal trips. Phuket and Koh Samui have different wettest months.
Most of Thailand broadly follows a mid-May–mid-October rainy season, mid-October–mid-February cooler season, mid-February–mid-May hot season. Actual season start dates vary each year. Bangkok remains hot during the day even in the cooler season, while Chiang Mai’s mornings and nights are cooler, so pack for each destination.
Phuket and Krabi on the Andaman coast become wetter during the southwest monsoon. Koh Samui on the southern east coast is affected by the northeast monsoon and has more rain towards the end of the year. Coastal weather patterns can therefore differ in the same month when you change destinations.
In the climate normals, Phuket receives 350.4mm in September and Koh Samui 444.6mm in November. Compare each destination’s twelve-month table, then check your travel-date forecast and boat operations.
No. Northern and central Thailand, the Andaman coast and the southern east coast have different wetter months. If choosing between Phuket or Krabi and Koh Samui, compare rainfall for the month you plan to travel.
Not necessarily. Eat or rest indoors during heavy rain and explore nearby places when it eases. Keep outdoor sightseeing times flexible. Swimming, boat journeys and island tours may need to change or be cancelled according to the day’s weather and local instructions, so read cancellation and change terms when booking.
No. The figures average weather observed during 1991–2020. They help compare travel months but do not predict the weather on your trip. Check the Thai Meteorological Department’s actual forecast for your dates before departure.
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