Thailand
Koh Samui in July: weather, sea & travel advice
This month's data profile
Rain shapes the decision
Koh Samui in July is climatically mixed. The average daily high is around 29 °C, and the sea is about 30 °C. With about 27 rainy days it is very wet.
Historical monthly averages, not a weather forecast. Individual days and years can differ substantially.
Rank among 12 monthly averages
54/100 · #10
Warmth
#4
Dryness
#10
Sun
#7
Sea warmth
#4
Published best categories: none
Koh Samui · JulyPhoto: Sonia Selivonchik · CC BY-SA 4.0Climate facts
- Average high
- 29 °C
- Average low
- 28 °C
- Sea
- 30 °C
- Rainy days (est.)
- 27 rainy days (est.)
- Sun (est.)
- 6 h/day
- Humidity
- 80 %
Climate evidence with direct month comparison
The highlighted row is the selected month. Precipitation total and rainy days are separate monthly averages.
| Month | Avg high °C | Avg low °C | Rainy days (est.) | Precipitation mm | Sun h/day (est.) | Humidity % | Wind m/s | Sea °C | Score |
|---|---|---|---|---|---|---|---|---|---|
| June | 30 | 28 | 25 | 164 | 6.4 | 80 | 4.0 | 30 | 52 |
| July (selected) | 29 | 28 | 27 | 172 | 6.3 | 80 | 4.3 | 30 | 54 |
| August | 29 | 27 | 27 | 163 | 6.5 | 81 | 4.4 | 29 | 55 |
How do the previous and next months compare?
Baseline: July (54/100)
Positive and negative values show the change from the selected month.
| Score Δ | Average high Δ | Average low Δ | Rainy days Δ | Rain Δ | Sun Δ | Humidity Δ | Wind Δ | Sea Δ | |
|---|---|---|---|---|---|---|---|---|---|
| June | -2 | +0.4 °C | +0.4 °C | -1.7 | -7.6 mm | +0.1 h | -0.8 % | -0.3 m/s | +0.4 °C |
| August | +1 | -0.1 °C | -0.2 °C | -0.3 | -8.6 mm | +0.2 h | +0.5 % | +0.1 m/s | -0.2 °C |
All twelve months in context
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Where to stay in Koh Samui
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Useful next decisions
Frequently asked questions
How warm is Koh Samui in July?
The average daily high is around 29 °C, with an average daily low of about 28 °C.
Can you swim in Koh Samui in July?
The sea is about 30 °C (very warm).
Does it rain a lot in Koh Samui in July?
The curated estimate is about 27 rainy days per month, not a directly measured long-term average. Total precipitation averages around 172 mm for the month. A rainy day does not mean all-day rain.
When is the best time to visit Koh Samui?
By the climate score, January, February, March and December are the strongest months for Koh Samui. For a beach trip: January, February, March and December. July is not among them.