August · Thailand
Best time to visit Koh Samui in August Weather, crowds & prices
Weather in Koh Samui in August
Average temperature 26°C, 112 mm of rain, about 27 days with 6+ hours of sunshine and 77% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
August score
8.0/10
Ranked #7 of 12 months
- Avg temp
- 26°C
- Rainfall
- 112 mm
- Humidity
- 77%
- Days with 6h+ sun
- 27
- Crowd Density
- Moderate Crowds
- Average Expenses
- $$ · Moderate Cost ($$)
August in Koh Samui scores 8.0/10 for beach and coastal travel - ranked #7 of 12. Expect around 26°C, 112 mm of rain, and roughly 27 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.
August holds up well in Koh Samui — 7th best month
August averages 26°C (78°F) — warm enough for beach and boat plans, still short of the heat that pushes sightseeing into early morning.
Monthly rainfall reaches 112 mm — wet for this destination — but about 27 days with 6+ hours of sunshine still break through, so keep one indoor fallback in the plan.
It scores 8/10 here, 7th of 12 months, against 9.3/10 in the destination's best month.
Pack light clothing, swimwear and real sun protection, a proper rain shell rather than an umbrella.
Plan for mid-season pricing, with crowds are moderate.
Frequently asked
- What is the weather like in Koh Samui in August?
- In August, Koh Samui averages 26°C, 112 mm of rain, and about 27 days with 6+ hours of sunshine. Its climate-comfort score is 8.0/10.
- Is August a good time to visit Koh Samui?
- August earns a 8.0/10 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 August?
- Expect about 112 mm of rain in August. Average humidity is 77% and there are about 27 days with 6+ hours of sunshine.
Curated in Koh Samui
Tickets & experiences
Things to do in Koh Samui
Koh Samui, Thailand. Live activities and tours from GetYourGuide, matched to this destination.