Temperatures & Rainfall average

Samui Temperatures and Rainfall

Koh Samui has generally 3 different seasons, hot season, dry season, and rainy season. The chart on the left shows the average temperatures and amount of rainfall for Samui.

Below in the columns we have some detailed information about each season, to make it easier for you to choose the right time for your holiday on Koh Samui.

Dry Season

December – February

It is usually the dry season on Koh Samui and on the southern west coast of Thailand.

It does not rain a lot, which means that waters quite calm, but it some occasional heavy rains for an hour or two might occur.

Hot Season

March – August

With quite dry, sunny and hot weather the months between March and August are called the hot season. March and April are in experience the hottest and driest months and in May it might start to rain more often. These showers are mostly not lasting very long, but can be heavy falls or thundershowers.

Actually this is the best season to visit Koh Samui, Koh Phangan, Koh Tao and the National Marine Park, if you are able to take the heat and stand temperatures between 28℃ – 40℃ during the day.

Rainy Season

September – November

Temperatures are still hot and usually in September there are still many sunny days. October and November are the months with the most rainy days and with the biggest volume of rainfall around the year.

Rainy Season or monsoon season does not mean, that it will be raining at all times, but rainfalls and thundershowers are very common and there might be times with non-stop rain for 5-6 days. Nevertheless this season is highly appreciated after a long period with hot and dry weather, you might even find yourself in a refreshing monsoon shower for a moment.

Most of the rain showers are short (rain showers in October and November might be lasting longer) and due to the finite water supplies of Koh Samui those rain showers are needed and important for Koh Samui’s flora and fauna. As the Angthong Marine Park is closed each year between November and mid December, Bluestars does not operate during November and mid December.