Koh Samui weather is really pleasant most of the time. The climate in Samui comes in three distinct seasons: dry, hot and rainy. Thailand lies between the Tropic of Cancer and the Equator (slightly closer to the latter). This makes its climate warm and humid all year round. The humidity level stands between 70 and 85 per cent, and the temperatures averages at around 28°C.
Koh Samui offers all that vacationers from cooler temperate countries could dream of regarding weather conditions. They are generally good year round, and the one thing you will rarely feel here is cold. You can enjoy the optimum weather conditions in Koh Samui between December and August.
Samui Weather Forecast
Average Rainfalls in Samui
Average Rainfalls in Samui obviously varies each year!
Koh Samui Weather in High Season
The high/dry season in Samui runs roughly from December to February. It offers warm yet bearable temperatures, little rain, calm seas, and light winds. Many consider this the time of the best Koh Samui weather, and the ideal time for a holiday here. For hotels and every tourist-related business, this is peak season.
Hot Season in Samui
The hottest time of year is between March and May. It is a great time to visit the island if you can stand 30°C+ temperatures. This period marks the beginning of the monsoon, as there is also an increase in rainfall. These rains permit both locals and visitors to cool off. Paradoxically, from June to August is also considered a mini-high season in Samui. Many vacationers make use of the long summer holiday period in Europe to visit Samui. In July and August, the weather usually follows a repeating pattern: daytime sunshine followed by late afternoon thunderstorms. It is indeed very agreeable.
September through to November sees the peak of the monsoon and, therefore, the heaviest rainfall. Even at this time, it doesn’t fall every day and often only in short bursts. Koh Samui weather forecasts become increasingly unreliable as the conditions become unpredictable. This is not the best time to come for a beach holiday, neither for scuba diving, as visibility is reduced by around 30 per cent. Besides, rougher seas and winds can make boat trips hazardous. The upsides of low season in Samui are that beaches are less crowded, and hotel rates are lower. Koh Samui also features a good choice of cool activities to keep you busy on rainy days.