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When is the best time to visit Ko Samui?
In general the best time to visit Ko Samui is probably June, when the weather is usually great. The hottest months are May, June, September, while the coldest months are January, February, October.
The best time to visit may differ depending on what you are looking for:
- The best time for a sunbathing holiday is May, June, September. Average maximum temperatures are up to +28°C in June and it has 0 sunny days on average.
- In general, it’s pleasant to walk and do outdoor activities during January - December.
- If you want to avoid wet weather, then your choice is October, November, December with the lowest chance of rain.
Average weather in Ko Samui in different months
This is the average weather in Ko Samui for each month based on historic data:
January, February usually has good weather. Average maximum temperature reaches +26°C during February.
In March, April, May, June, July, August, September, October, November, December the weather is average. Expect around 151 rainy days, and the precipitation amounts to approximately 278 mm in November.
Climate in Ko Samui
Here is the detailed breakdown of the climate in Ko Samui for each month:
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum Temperature | |||||||||||
| +30°C | +32°C | +31°C | +33°C | +34°C | +33°C | +33°C | +33°C | +32°C | +32°C | +30°C | +30°C |
| Average Maximum Temperature | |||||||||||
| +25°C | +26°C | +27°C | +27°C | +28°C | +28°C | +27°C | +27°C | +27°C | +26°C | +26°C | +26°C |
| Minimum Temperature | |||||||||||
| +18°C | +17°C | +21°C | +21°C | +21°C | +21°C | +21°C | +20°C | +21°C | +21°C | +19°C | +20°C |
| Avg. water temperature | |||||||||||
| +29°C | +29°C | +30°C | +32°C | +31°C | +31°C | +31°C | +30°C | +30°C | +30°C | +30°C | +30°C |
| Humidity, % | |||||||||||
| 79 | 78 | 78 | 78 | 78 | 77 | 77 | 78 | 79 | 82 | 82 | 79 |
| Rain, mm | |||||||||||
| 47 | 29 | 60 | 86 | 116 | 82 | 82 | 85 | 142 | 242 | 278 | 115 |
| Snow, mm | |||||||||||
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Average wind speed, m/s | |||||||||||
| 3 | 3 | 3 | 2 | 2 | 3 | 3 | 3 | 3 | 2 | 3 | 3 |
| Sunny Days | |||||||||||
| 3 | 5 | 6 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 2 |
| Cloud Days | |||||||||||
| 11 | 11 | 10 | 6 | 2 | 4 | 3 | 4 | 2 | 2 | 3 | 10 |
| Rainy Days | |||||||||||
| 16 | 11 | 11 | 12 | 12 | 15 | 17 | 18 | 17 | 16 | 17 | 16 |
| Snowy Days | |||||||||||
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Average Temperature
Here are the average maximum and minimum temperatures in Ko Samui during the whole year:
The hottest month in Ko Samui is June with average maximum temperature going up to +28°C. The coldest month is January with the lowest temperatures of +24°C.
Water temperature
Here are the water temperatures in Ko Samui during the whole year:
Ko Samui achieves its warmest water temperature in May, where the average sea temperature goes up to +30°C. Coldest water temperature is in January with +28°C in average.
When can you swim in Ko Samui?
You can swim in Ko Samui from January to December:
- In February - December the water is very warm (28°C);
- In January the water is warm (25°C - 28°C);
Humidity
The temperature feels different depending on humidity. Here is how humidity in Ko Samui looks throughout the year, in %:
The most humid month in Ko Samui is November with average humidity going up to 82%. The least humid month is June with an average humidity of 77%.
Rain
Amount of rainfall in mm. in Ko Samui during the whole year based on historical data:
The sunniest and driest month is March with approximately 6 sunny days and a total precipitation of around 60 mm. The rainiest and wettest month is November with approximately 17 rainy days and 278 mm of total precipitation.
FAQ
Frequently asked questions about the weather in Ko Samui:
What is the hottest month in Ko Samui?
The hottest month in Ko Samui is June with average maximum temperature of +28°C.
What is the coldest month in Ko Samui?
The coldest month in Ko Samui is January with minimum temperatures of +24°C.
Is Ko Samui worth visiting in winter?
If you are planning to visit Ko Samui in winter you can expect pretty good weather. The best month is June with +28°C and 0 sunny days.
When does it rain the least in Ko Samui?
if you're looking to visit Ko Samui when it rains the least, you should plan your trip for November, October, September. During this time, rainfall is rare with the driest month being February with only 29 mm of rain.
Other cities in Thailand
Check out the weather for other cities in Thailand.
Monthly weather in Ko Samui
Source of the data
For this page, we’ve looked at the typical weather in Ko Samui, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.