Since Samui is an island, the weather doesn’t differ much during the year. Samui’s weather patterns are a little different from the rest of Thailand. In April through September, when most of the country has its monsoon, Samui stays fairly dry, but from October to December, it’s wet in Samui and drier elsewhere. The driest season is from January to March.

The lowest average temperature is at 25 degree Celsius and the highest is at 35.

time to visit the island is without a doubt from December through June. Coming in the off months means heavy rains and potentially torrential storms.

Ko Samui weather can become very hot; those affected by weather should consider what month is best for them. December to February is traditionally the best time to go. March through June remains high-season but temperatures climb is slightly heigher. Plenty of sunshine and very little rain exists during this period. October and November are the rainiest months, however, compared to main land Thailand, Ko Samui does not suffer nearly as much rain  (as opposed to the Andaman coast side of Thailand) during what’s considered the “rainy season”.