Ko Samui weather in January
January in Ko Samui: hot, a little rain, with very humid — an excellent time to visit.
#5 of 12 months in Ko Samui · #136 of 604 destinations to visit in January · comfort 82/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Ko Samui climate normals — January
| Daytime high | 28°C / 82°F | 🥵 hot |
|---|---|---|
| Nighttime low | 26°C / 79°F | |
| Feels like (high) | 32°C / 90°F | |
| Rainfall | 60 mm / 2.4 in | 🌦 some rain |
| Rainy days | 7 days | |
| Humidity | 76% | 💦 very humid |
| Dew point | 22°C / 72°F | |
| Sunshine | 10.4 h/day | |
| Daylight | 11.6 h | |
| Wind | 23 km/h / 14 mph | |
| Air quality (US AQI) | 62 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Ko Samui?
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Ko Samui in January — FAQ
- Is January a good time to visit Ko Samui?
- January in Ko Samui: hot, a little rain, with very humid — an excellent time to visit. It ranks #5 of 12 months for Ko Samui on SeasonMap's comfort score (82/100).
- What is the weather like in Ko Samui in January?
- In January, Ko Samui averages a daily high of 27.8°C and a low of 25.9°C, with about 60 mm of rain over roughly 7 rainy days.
- What is the air quality in Ko Samui in January?
- Ko Samui has a mean US Air Quality Index of about 62 in January.