Climate Chart of Koh Samui, Thailand
Monthly data: Temperature °C, Rain (mm), Sunshine (h) · 2013–2023
For Koh Samui, Thailand, the climate data cover 2013–2023. Monthly mean temperatures remain warm through the year: the lowest supplied monthly mean is January at 26.5 °C, while the highest is May at 28.9 °C. Daily rainfall and sunshine also show distinct monthly highs and lows, giving visitors useful planning cues without guaranteeing the conditions on any particular day.
Climate overview
Temperature
Monthly mean temperatures range from January at 26.5 °C to May at 28.9 °C. These are averages for each month, not daytime maximum temperatures, so they describe the broad temperature pattern rather than the hottest part of a typical day. The unweighted mean across the monthly means is 27.7 °C. It provides a compact overview of the supplied monthly averages, but is not a day-weighted annual average.
Rain
Mean daily rainfall is highest in November at 9.33 mm/day and lowest in March at 1.12 mm/day. These are daily averages for the named months, not monthly rainfall totals, and the lower mean does not guarantee rain-free days or indicate how often rain occurs. The unweighted mean across the monthly daily-rainfall means is 4.23 mm/day. It offers a broad comparison point rather than a day-weighted annual average.
Sunshine
Mean daily sunshine reaches its supplied high in March at 10.87 hours/day, and its low in November at 8.31 hours/day. These averages can help with outdoor planning, but sunshine duration is not the same as day length and does not determine the conditions on an individual day. Across the calendar-month means, the unweighted mean daily sunshine duration is 9.64 hours/day; this summary is not a day-weighted annual average.
Best Travel Time Guide for Koh Samui, Thailand: Ideal Seasons and Weather Insights
For visitors prioritising lower average rainfall, March is the conditional option to consider, with mean daily rainfall of 1.12 mm/day. That monthly average cannot promise dry days or quantify rain frequency, so flexible plans and rain preparation remain sensible. Visitors prioritising cooler monthly averages can look to January, when the monthly mean temperature is 26.5 °C; this is not a daytime high. For outdoor sightseeing, the mean daily sunshine high in March is 10.87 hours/day, while the low in November is 8.31 hours/day. Sunshine duration helps frame daylight outdoor planning but is not day length.
Rain preparation is especially relevant to November, which has the highest supplied mean daily rainfall at 9.33 mm/day. This average does not specify how many days will be wet, so it is best used as a planning cue rather than a forecast.
Climate Data Overview for Koh Samui, Thailand
Explore the comprehensive climate data for Koh Samui, Thailand. This detailed table provides valuable insights into temperature variations, precipitation levels, and seasonal changes, helping you understand the unique weather patterns of this region.
| Month | Average: Temperature °C | Rain (mm) / day | Snow (mm) / day | Sunshine (h) / day |
|---|---|---|---|---|
| Jan | 26.5 | 3.75 | 0.00 | 10.15 |
| Feb | 26.8 | 1.63 | 0.00 | 10.66 |
| Mar | 27.9 | 1.12 | 0.00 | 10.87 |
| Apr | 28.7 | 4.22 | 0.00 | 10.43 |
| May | 28.9 | 3.69 | 0.00 | 10.35 |
| Jun | 28.7 | 2.77 | 0.00 | 9.72 |
| Jul | 28.4 | 3.26 | 0.00 | 9.15 |
| Aug | 28.3 | 2.98 | 0.00 | 9.51 |
| Sep | 27.7 | 4.73 | 0.00 | 8.59 |
| Oct | 27.1 | 7.19 | 0.00 | 8.61 |
| Nov | 26.9 | 9.33 | 0.00 | 8.31 |
| Dec | 26.6 | 6.12 | 0.00 | 9.33 |
| Average | 27.7 | 4.23 | 0.00 | 9.64 |
