Best time to visit Koh Samui
Gulf of Thailand island, its rains offset from Phuket's
- Highest-rated months
- February, March, April
- Other good months
- January, May, June, July, August
- Less favorable months
- October, November, December
Editorial seasonal ratings describe conditions for a trip. They are not safety ratings or weather forecasts.
This destination has its own seasonal assessment.
Travel advisory snapshot
US advisory level 1
Snapshot checked 2026-10-13. Read current official guidance before booking. Seasonal suitability does not override a travel advisory.
Read the official advisoryWeather by month
| Month | Seasonal rating | Daytime high | Nighttime low | Rainfall | Sea temperature | Seasonal reasons |
|---|---|---|---|---|---|---|
| January 2027 | 30°C / 86°F | 23.8°C / 75°F | 112 mm | 27.8°C / 82°F | Beach weather, Rainy season | |
| February 2027 | 30.6°C / 87°F | 24.5°C / 76°F | 48 mm | 28.2°C / 83°F | Beach weather, Dry season | |
| March 2027 | 31.9°C / 89°F | 25.2°C / 77°F | 107 mm | 28.9°C / 84°F | Beach weather, Dry season | |
| April 2027 | 33.1°C / 92°F | 25.8°C / 78°F | 89 mm | 30°C / 86°F | Beach weather, Dry season, Scorching heat, Songkran | |
| May 2027 | 33.4°C / 92°F | 25.7°C / 78°F | 125 mm | 30.3°C / 87°F | Beach weather, Scorching heat | |
| June 2027 | 32.5°C / 91°F | 25.6°C / 78°F | 89 mm | 30°C / 86°F | Beach weather | |
| July 2027 | 32.5°C / 91°F | 25.4°C / 78°F | 85 mm | 29.7°C / 85°F | Beach weather | |
| August 2027 | 32.2°C / 90°F | 25.3°C / 78°F | 92 mm | 29.4°C / 85°F | Beach weather | |
| September 2027 | 31.8°C / 89°F | 24.8°C / 77°F | 116 mm | 29.2°C / 85°F | Rainy season | |
| October 2026 | 31°C / 88°F | 24.4°C / 76°F | 265 mm | 29°C / 84°F | Rainy season | |
| November 2026 | 30.1°C / 86°F | 24.2°C / 76°F | 372 mm | 28.5°C / 83°F | Monsoon downpours | |
| December 2026 | 29.8°C / 86°F | 23.8°C / 75°F | 236 mm | 28°C / 82°F | Rainy season |
Scroll the table horizontally to see every column.
Long-term averages, not a forecast. Temperature and rainfall: 1991–2020; humidity and cloud: 2001–2020; sea temperature: 1991–2020. Climate snapshot prepared 2026-10-04.
Event adjustments refer to the next occurrence of each month as of 2026-10-14; the year is shown in the table.
Local food and lodging costs
National price level: 26, with the United States at 100. Reference year: 2025. This is a relative food and lodging indicator, not a trip budget; flights are excluded.
Keep exploring
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Explore Thailand by seasonPlanning with this guide
When is the best time to visit Koh Samui?
The highest seasonal ratings in this assessment are in February, March, April. Compare the monthly reasons and climate below before choosing your dates. Editorial seasonal ratings describe conditions for a trip. They are not safety ratings or weather forecasts.
Do good seasonal ratings mean it is safe to travel?
No. Seasonal ratings describe timing, weather and experiences. Check current official travel advisories, entry requirements and local conditions before booking.
Sources and limits
This tool uses stored snapshots and is not updated in real time. Climate averages are not forecasts, and seasonal ratings are not safety assessments. Information may be incomplete or out of date. Before booking, check current official travel advisories, entry requirements, weather forecasts and local conditions.
TerraClimate · NASA POWER · NOAA OISST · Copernicus DEM GLO-90 (2021)
How it works and data sources · Sources and third-party licenses