January · Thailand
Best time to visit Koh Samui in January Weather, crowds & prices
Weather in Koh Samui in January
Average temperature 24°C, 56 mm of rain, about 30 days with 6+ hours of sunshine and 78% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
January score
9.1/10
Ranked #2 of 12 months
- Avg temp
- 24°C
- Rainfall
- 56 mm
- Humidity
- 78%
- Days with 6h+ sun
- 30
- Crowd Density
- Peak Tourist Rush
- Average Expenses
- $$$ · Peak Season Rates ($$$)
January in Koh Samui scores 9.1/10 for beach and coastal travel - one of the top 12-month picks (#2). Expect around 24°C, 56 mm of rain, and roughly 30 days with 6+ hours of sunshine this month.
Koh Samui's ring road links Chaweng's beach, Bophut's Fisherman's Village, and the Big Buddha on the north coast.
January is one of the strongest months in Koh Samui (2nd)
With 24°C (75°F) on average, January delivers classic beach weather: plenty of time in the water, with beach and boat plans rarely disrupted by cold.
Budget for roughly 56 mm of rain this month — a flexible day or two helps — with about 30 days with 6+ hours of sunshine and 11.6 hours of daylight to work around it.
On our climate-comfort scale this is one of the strongest months of the year for Koh Samui at 9.1/10 (2nd of 12), just behind March at 9.3/10.
Pack light clothing, swimwear and real sun protection, a packable rain layer.
Budget for peak pricing, and this is one of the busiest months here. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Frequently asked
- What is the weather like in Koh Samui in January?
- In January, Koh Samui averages 24°C, 56 mm of rain, and about 30 days with 6+ hours of sunshine. Its climate-comfort score is 9.1/10.
- Is January a good time to visit Koh Samui?
- January earns a 9.1/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Koh Samui in January?
- Expect about 56 mm of rain in January. Average humidity is 78% and there are about 30 days with 6+ hours of sunshine.
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Koh Samui, Thailand. Live activities and tours from GetYourGuide, matched to this destination.