Climate Insights for Ko Samui

The climate in Ko Samui is hot. The average annual temperature is 28°C and approximately 1,674 mm of precipitation falls per year. Ko Samui receives a notable amount of rainfall throughout the year, including during its driest month. Ko Samui sits near the equator, so seasonal temperature differences are minimal throughout the year.The climate in Ko Samui is hot. The average annual temperature is 82°F and approximately 65.9 in of precipitation falls per year. Ko Samui receives a notable amount of rainfall throughout the year, including during its driest month. Ko Samui sits near the equator, so seasonal temperature differences are minimal throughout the year.

Ko Samui has relatively stable temperatures year-round, staying within a 4°C range. The warmest month is May, when average highs reach 30°C and the mean temperature sits around 29°C. December is the coolest month, with minimum temperatures around 26°C and an average of 27°C. Daily temperature variation is modest, with an average difference of 2°C between highs and lows.Ko Samui has relatively stable temperatures year-round, staying within a 6°F range. The warmest month is May, when average highs reach 85°F and the mean temperature sits around 84°F. December is the coolest month, with minimum temperatures around 79°F and an average of 80°F. Daily temperature variation is modest, with an average difference of 3°F between highs and lows.

Ko Samui is a fairly wet location, receiving approximately 1,674 mm of precipitation annually, which averages out to around 140 mm per month. The wettest month is November, averaging 322 mm of rainfall. October and December also tend to see above-average precipitation. The driest month is March, with just 38 mm. That's 284 mm less than November, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.Ko Samui is a fairly wet location, receiving approximately 65.9 in of precipitation annually, which averages out to around 5.5 in per month. The wettest month is November, averaging 12.7 in of rainfall. October and December also tend to see above-average precipitation. The driest month is March, with just 1.5 in. That's 11.2 in less than November, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

Ko Samui is mildly breezy, with an average annual wind speed of 16km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is December, averaging 18km/h, though still comfortable for most outdoor activities. The calmest conditions occur in April, with average winds dropping to 14km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 4km/h between the calmest and windiest months.Ko Samui is moderately windy, with an average annual wind speed of 10mph. For context, sustained winds below 7mph are generally light, while anything above 16mph is considered strong. The windiest month is December, averaging 11mph, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in April, with average winds dropping to 8mph, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3mph between the calmest and windiest months.

The table below shows monthly climate averages for Ko Samui based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.The table below shows monthly climate averages for Ko Samui based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Fahrenheit (°F). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in miles per hour (mph). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.