Koh Samui weather in March
Temperature, sea and sunshine in March: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in March
Excellent
Best time to visit: January – April
What is the weather like in Koh Samui in March?
In March, Koh Samui is hot: daytime highs average 29 °C, and even at night it stays warm at around 27 °C. The sea averages 29.1 °C – almost as warm as a bath. The sun shines for around 8 hours a day. Rain falls on about 9 days, adding up to 77 mm. The air is often humid and muggy. All in all, March is an excellent month for a holiday in Koh Samui.
March compared
How the weather changes from February to April. Tap a month to open it.
| FebruaryFeb | MarchMar | AprilApr | |
|---|---|---|---|
| Score | 93 | 90 | 82 |
| Day | 28° | 29° | 30° |
| Night | 26° | 27° | 28° |
| Sea | 28° | 29° | 30° |
| Sun | 8 h | 8 h | 8 h |
| Rain days | 6 | 9 | 14 |
More details for March
- Daylight
- 12 h 3 min06:28 – 18:32
- UV index
- 13 · extremeclear sky, noon (estimate)All months
- Muggy days
- 31 daysdew point 18 °C or more
- Wind
- 16 km/haverage daily peak
- Cloud cover
- 51 %on average
- Hot days
- 5 days30 °C or more
- Time zone
- UTC+7Asia/Bangkok
How the score comes together
- Temperatureweight 35 %100 %
- Seaweight 25 %100 %
- Sunshineweight 20 %85 %
- Few rainy daysweight 20 %67 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in March
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Insect repellent
- Rain jacket or umbrella
Koh Samui in March: quick answers
Is Koh Samui hot in March?
Yes. In March, Koh Samui is hot: daytime highs average 29 °C and nights stay around 27 °C. On about 5 days the thermometer climbs to 30 °C or more.
Can you swim in Koh Samui in March?
Yes. In March the sea averages 29.1 °C – almost as warm as a bath.
Does it rain much in Koh Samui in March?
Rain falls on about 9 days, adding up to 77 mm.
Koh Samui month by month
The whole year in Koh SamuiAll destinations: ThailandWhere to go in MarchSea temperature in March
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0)