🇹🇭 Weather in Koh Samui in July
This is what the weather in Koh Samui (Thailand) was like in July in 2017–2026.
Key facts at a glance
Avg. daytime high
29.6 °C
29.2 °C – 30.0 °C
Avg. night-time low
27.9 °C
27.5 °C – 28.3 °C
Avg. rain days in period
26.9
87 % of days · ≥ 1.0 mm
Avg. precipitation in period
187 mm
87.1 mm – 243 mm
Avg. sunshine per day
n/a
Sunshine duration is not available from this data source.
Avg. sea temperature
30.3 °C
Sea point approx. 10 km from the location
Extremes: Highest temperature 31.2 °C (21 Jul 2024) · Lowest temperature 26.9 °C (8 Jul 2017) · Avg. daily peak wind 22 km/h
Weather mix of all days
- 10Partly cloudy
- 31Cloudy
- 139Light rain
- 130Rain
Summary
- On average 29.6 °C during the day and 27.9 °C at night.
- On average 26.9 rain days (Rain day = at least 1.0 mm of precipitation) with 187 mm of precipitation in total.
- The sea averaged 30.3 °C.
- Prevailing: Light rain.
- Warmest year: 2026 (avg. 30.0 °C), coolest: 2017 (avg. 29.2 °C).
- Wettest year: 2020 (243 mm), driest: 2025 (87.1 mm).
- Extremes: 31.2 °C on 21 Jul 2024 and 26.9 °C on 8 Jul 2017.
Overall values from all 10 years. How is this calculated?
Charts
Temperatures per year
Average over your travel period
Precipitation & rain days
Year by year
2026
Avg. max30.0°Avg. min28.3°- Rain days
- 28 Rain days
- Precipitation
- 169 mm
- Avg. sunshine per day
- n/a
- Sea temperature
- 30.9 °C
Max 31.0 °C · Min 27.6 °C
2025
Avg. max29.7°Avg. min27.9°- Rain days
- 23 Rain days
- Precipitation
- 87.1 mm
- Avg. cloud cover
- 84 % cloudy
- Sea temperature
- 30.0 °C
Max 30.8 °C · Min 27.5 °C
2024
Avg. max30.0°Avg. min28.1°- Rain days
- 30 Rain days
- Precipitation
- 239 mm
- Avg. cloud cover
- 97 % cloudy
- Sea temperature
- 30.7 °C
Max 31.2 °C · Min 27.4 °C
2023
Avg. max29.8°Avg. min28.1°- Rain days
- 26 Rain days
- Precipitation
- 233 mm
- Avg. cloud cover
- 91 % cloudy
- Sea temperature
- 30.2 °C
Max 31.0 °C · Min 27.2 °C
2022
Avg. max29.3°Avg. min27.8°- Rain days
- 30 Rain days
- Precipitation
- 238 mm
- Avg. cloud cover
- 92 % cloudy
- Sea temperature
- 29.9 °C
Max 29.9 °C · Min 27.1 °C
2021
Avg. max29.5°Avg. min27.9°- Rain days
- 26 Rain days
- Precipitation
- 199 mm
- Avg. cloud cover
- 91 % cloudy
- Sea temperature
- 29.9 °C
Max 30.6 °C · Min 27.1 °C
2020
Avg. max29.2°Avg. min28.0°- Rain days
- 28 Rain days
- Precipitation
- 243 mm
- Avg. cloud cover
- 92 % cloudy
- Sea temperature
- 30.8 °C
Max 30.2 °C · Min 27.0 °C
2019
Avg. max29.9°Avg. min28.1°- Rain days
- 24 Rain days
- Precipitation
- 146 mm
- Avg. cloud cover
- 88 % cloudy
- Sea temperature
- 30.7 °C
Max 30.7 °C · Min 27.1 °C
2018
Avg. max29.3°Avg. min27.5°- Rain days
- 25 Rain days
- Precipitation
- 166 mm
- Avg. cloud cover
- 93 % cloudy
- Sea temperature
- 29.4 °C
Max 30.0 °C · Min 26.9 °C
2017
Avg. max29.2°Avg. min27.6°- Rain days
- 29 Rain days
- Precipitation
- 148 mm
- Avg. cloud cover
- 93 % cloudy
- Sea temperature
- 30.2 °C
Max 30.3 °C · Min 26.9 °C
Frequently asked questions
- How warm is it in Koh Samui in July?
- Daytime highs averaged 29.6 °C, night-time lows 27.9 °C. The highest value of the past 10 years was 31.2 °C (21 Jul 2024), the lowest 26.9 °C (8 Jul 2017).
- How often does it rain in Koh Samui in July?
- On average there were 26.9 rain days (at least 1 mm) with 187 mm of precipitation in total.
- How warm is the sea in Koh Samui in July?
- The sea temperature averaged 30.3 °C (open-sea point approx. 10 km from the town).
Check your exact travel dates
Choose your travel period – we show the weather for exactly those days.
Other destinations in July
Data sources
- Weather data
- Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains. - Sea temperature
- MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis) - Sea point approx. 10 km from the location (9.430, 100.040)
- Place search
- Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)