Weather by month · Koh Samui
Koh Samui weather by month for Muay Thai training
No month has under 30 mm of rain. Wettest: November (489.6 mm). Hottest: May (highs 32.6°C). Official long-term figures from the Thai Meteorological Department.
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Koh Samui month by month
| Month | Rain | Rain days | Daytime high | Night low | In plain words |
|---|---|---|---|---|---|
| Jan | 137.8 mm | 11 | 29°C | 24.1°C | wet; warm afternoons, warm nights |
| Feb | 57.8 mm | 5.5 | 29.5°C | 25°C | some rain; warm afternoons, warm nights |
| Mar | 77.8 mm | 5 | 30.7°C | 25.6°C | some rain; warm to hot afternoons, warm nights |
| Apr | 76.6 mm | 8.1 | 32.1°C | 26.1°C | some rain; warm to hot afternoons, warm nights |
| May | 146.5 mm | 14.8 | 32.6°C | 25.8°C | wet; warm to hot afternoons, warm nights |
| Jun | 112.7 mm | 14.5 | 32.2°C | 25.5°C | wet; warm to hot afternoons, warm nights |
| Jul | 122.8 mm | 14.4 | 32°C | 25.1°C | wet; warm to hot afternoons, warm nights |
| Aug | 118.7 mm | 15 | 31.9°C | 25.1°C | wet; warm to hot afternoons, warm nights |
| Sep | 116.8 mm | 15.9 | 31.6°C | 24.8°C | wet; warm to hot afternoons, warm nights |
| Oct | 290.2 mm | 19.7 | 30.5°C | 24.4°C | very wet; warm to hot afternoons, warm nights |
| Nov | 489.6 mm | 19.6 | 29.5°C | 24.1°C | the wettest kind of month; warm afternoons, warm nights |
| Dec | 209.1 mm | 14 | 29.1°C | 23.9°C | very wet; warm afternoons, warm nights |
Also the nearest official figures for Koh Phangan (no station of its own; Koh Samui's figures are the nearest, about 20 km away).
Training in the heat
- The NHS says to drink extra fluids in hot weather and to go easy on alcohol, caffeine and hot drinks.
- It also says to stay out of the sun between 11am and 3pm and to avoid activity that makes you hotter. Many camps train early morning and late afternoon; check the camp's own timetable.
- Know the signs of heat exhaustion the NHS lists: tiredness, dizziness, headache, feeling sick, heavy sweating, cramps, a high temperature and being very thirsty. Move somewhere cool, drink water and cool the skin; you should feel better within 30 minutes.
- Heatstroke is an emergency (very high temperature, hot skin that isn't sweating, confusion, fast breathing). Get urgent medical help.
General information, not medical advice. Sources: NHS: heatwave, how to cope in hot weather; NHS: heat exhaustion and heatstroke (both read 1 Nov 2026).
Plan around it
Questions
What is the weather like in Koh Samui by month?
No month has under 30 mm of rain. Wettest: November (489.6 mm). Hottest: May (highs 32.6°C). Official long-term figures from the Thai Meteorological Department.
What is the rainy season in Koh Samui?
The official figures show the most rain in November (489.6 mm). The table shows every month's rain and rain days.
When is the best time to train Muay Thai in Koh Samui?
Every month has some rain in the official figures; the table shows which months have the least.
Is it too hot to train?
Many people train all year, mostly early morning and late afternoon. The NHS advice is to drink extra fluids, keep out of the midday sun and know the signs of heat exhaustion. General information, not medical advice.
Where do these figures come from?
The Thai Meteorological Department's official long-term figures for the area's weather station, as published on the WMO World Weather Information Service.
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