When is the best time to visit Koh Samui?
For greater beach weather, less rainfall, and fewer crowds, I prefer visiting Koh Samui between February and June. Of these months, February and March experience the least rain throughout the year while May and June may see some showers, sometimes heavy showers. However, these months are exceptional for sightseeing as well as obtaining discounts on flights and lodgings.
- Ideal Time to Visit Koh Samui for Favorable Weather: Late December through April experiences ideal conditions with minimal rainfall and abundant sunshine. From May to September there remains ample sunlight but brief showers are probable – usually in the afternoon or evening. October and November are wetter periods when beach weather is harder to find.
- Optimal Time for Floating, Scuba Diving, and Day Trips to Angthong Marine Park: Koh Samui is not renowned for its floating or scuba diving but day excursions to Koh Tao are popular. The best time for diving on Koh Tao is anytime outside of November and early December with March, April, and May the best months to see huge whale sharks. Kayaking journeys to Angthong Marine Park are also a highlight of a trip to Koh Samui and they’re best from late December to September with the park being closed every year in November and early December.
- Best Timeframe to Save Funds: Visiting during the wet months of October and November will certainly acquire you some exceptional deals on lodgings. While the climate can be stormy during this period sunny days are still possible. A improved mix of good weather and prices is found during the months of April, May, and June. These months are hot and humid but very sunny and not a lot of tourists.
- High Season (late December, January, July and August): These months provide great beach weather with sunny and warm conditions, though not as intensely hot as April and May. Expect some rain but it usually passes quickly. Book the Best Koh Samui Hotels and the Best Koh Samui Family Hotels well in advance – especially for the weeks surrounding Christmas and New Years.
- Shoulder Season (February, March, April, May, June, September, early December): Great beach weather with February and March being the 2 driest and sunniest months to enjoy visiting Koh Samui.
- Low Season (October and November): The rainiest months of the year but it’s still possible to have a string of nice days.
Koh Samui Weather by Month
Temperature by Month (high in Celsius)
Rain by Month (mm)
- January Weather on Koh Samui: Fantastic beach conditions with lots of sunshine and little precipitation. (Average Maximum Temperature: 28°C. Average Rainfall: 40mm. Days with Precipitation: 7)
- Weather in February on Koh Samui: Fantastic beach conditions. February and March are the sunniest and driest months on Koh Samui. (Average Maximum Temperature: 29°C. Average Rainfall: 10mm. Days with Rainfall: 5)
- March Weather on Koh Samui: Excellent beach conditions with many sunny days. (Average Max Temperature: 31°C. Average Rainfall: 10mm. Days with Rainfall: 4)
- April Weather on Koh Samui: Great beach weather with lots of sun and little rain. (Average Max Temperature: 32°C. Average Rainfall: 70mm. Days with Rain: 5)
- May Weather on Koh Samui: Good beach weather. Sunny but more rain and humidity. (Average Max Temperature: 33°C. Average Rainfall: 180mm. Days with Rain: 9)
- The typical weather pattern on the island of Koh Samui in June includes: Hot and humid conditions with some rainfall. On average, the maximum daily temperature is around 32°C and rainfall totals approximately 100mm over 9 days that see measurable precipitation.
- July Weather in Koh Samui: Good beach conditions. Hot, humid, and some rainfall. (Average Maximum Temperature: 32°C. Average Rainfall: 130mm. Days with Precipitation: 10)
- August Weather on Koh Samui: Good beach weather. Hot, humid, and some precipitation. (Average Max Temperature: 32°C. Average Rainfall: 110mm. Days with Rain: 9)
- September Weather on Koh Samui: Good beach weather. Hot, humid, and some rain. (Average Max Temperature: 31°C. Average Rainfall: 190mm. Days with Rain: 11)
- October Weather on Koh Samui: There will be substantial rain during this period but some sunny days are still expected. (Average Maximum Temperature: 29°C. Average Rainfall: 260mm. Days with Rainfall: 15)
- Weather in November on Koh Samui: The rainiest month of the year. However, nice beach weather remains possible despite more rain. (Average Maximum Temperature: 28°C. Average Rainfall: 290mm. Days with Rainfall: 16)
- December Weather on Koh Samui: Good beach weather. Some rainfall at the beginning of the month but sunny dry days are the norm after December 20. (Average Max Temperature: 27°C. Average Rainfall: 90mm. Days with Rain: 8)
