Weather in Ko Samui in July 2025
Average weather
Average temperature in Ko Samui in July
The temperature in July is +27°C on average, with a range between a maximum of +29°C during the day and a minimum of +24°C at night.
The average maximum temperature goes up 0% by the end of the month, compared with the beginning of the month, from +27°C to +27°C.
Is Ko Samui warm or cold in July?
Ko Samui is typically warm in July.
Maximum temperatures go down compared to the previous month from +28°C to +27°C. The minimum temperature also goes up from +25°C to +25°C.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how July is compared to other months in Ko Samui:
Water temperature in Ko Samui in July
Water in Ko Samui in July is Very warm. It varies from +29°C to +31°C, with an average of +30°C. Note that the air temperature is lower than the water temperature, averaging around +27°C.
The water temperature in July is one of the warmest of the entire year:
Can you swim in Ko Samui in July?
Climate in Ko Samui in July
| June | July | August | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +28°C | +27°C | +27°C | ||||
| Min. temperature | ||||||
| +21°C | +21°C | +20°C | ||||
| Max. temperature | ||||||
| +33°C | +33°C | +33°C | ||||
| Rainfall | ||||||
| 82 mm | 82 mm | 85 mm | ||||
| Wind | ||||||
| 3 m/s | 3 m/s | 3 m/s | ||||
| Avg. water temperature | ||||||
| +30°C | +30°C | +29°C | ||||
| Humidity | ||||||
| 77% | 77% | 78% | ||||
| Air pressure | ||||||
| 1007 HPa | 1008 HPa | 1008 HPa | ||||
| Sunny days | ||||||
| 0 | 0 | 0 | ||||
| Cloudy days | ||||||
| 4 | 3 | 4 | ||||
| Rainy days | ||||||
| 15 | 17 | 18 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
July weather is still as ok as in June. It’s getting colder in July. From +28°C in the day, the average maximum temperature lowers to +27°C. The rainfall amount in July stays the same as in the previous month with a 82 mm of total precipitation. Humidity levels don’t change as the month goes on, averaging around 77%. The average wind speed doesn’t change much during July, staying around 3 m/s. The amount of sunny days stay about the same, averaging 0 sunny days during the month.
August brings much the same weather, it remains ok.
Wind
The average wind speed is 3 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Ko Samui is gradually decreasing during July, going from 4 m/s to 3 m/s over the course of the month.
Rain
How was the weather last July in Ko Samui?
Climate Change over Years
The climate in Ko Samui in July has not changed much over the last 43 years.
The average temperature was the lowest in 1986 (+26°C) and the highest in 2012 (+28°C). The driest year was 1997 with only 927 mm of rainfall, and the wettest year was 1999 with 1981 mm.
FAQ
Is July a good time to visit Ko Samui?
Can you sunbathe in Ko Samui in July?
Can you swim in Ko Samui in July?
Is Ko Samui rainy in July?
Is it sunny in Ko Samui in July?
Other cities in Thailand
Monthly weather in Ko Samui
Source of the data
For this page, we’ve looked at the typical weather in Ko Samui, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.