Whether you're visiting Koh Samui in Thailand during the peak of May (31°C (88°F)) or the cooler months around January (28°C (82°F)), knowing what to pack starts with understanding the local climate. Our overview is based on data from Chaweng Beach, the region's most prominent city. For more detailed climate information about other cities in the area, please see the section beneath the map further down the page.
In Koh Samui, particularly in Chaweng Beach, temperatures are consistently high throughout the year, with average maximum temperatures always above 28°C (82°F).
April, May and June are generally the hottest months of the year.
When it comes to rainfall, Koh Samui sees significant variations throughout the year. October tends to be the wettest, receiving 301 mm (12 in) of rain, while February is much drier with just 44 mm (1.7 in). Travelers should note that the rainy season falls during October and November, bringing substantial precipitation ranging from 294 mm (12 in) to 301 mm (12 in) monthly.
For those seeking sunshine, March usually has the brightest skies, making it an excellent time for exploring the region.
