Weather in Ko Samui in October 2025
Average weather
Average temperature in Ko Samui in October
The temperature in October is +81°F on average, with a range between a maximum of +82°F during the day and a minimum of +73°F at night.
The average maximum temperature goes down 20% by the end of the month, compared with the beginning of the month, from +81°F to +79°F.
Is Ko Samui warm or cold in October?
Ko Samui is typically warm in October.
Maximum temperatures go down compared to the previous month from +81°F to +79°F. The minimum temperature also goes up from +75°F to +75°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
October is one of the coolest months in Ko Samui, here is the comparison with other months:
Water temperature in Ko Samui in October
Water in Ko Samui in October is Very warm. It varies from +82°F to +87°F, with an average of +85°F. Note that the air temperature is lower than the water temperature, averaging around +79°F.
In October, water temperatures are average relative to the rest of the year:
Can you swim in Ko Samui in October?
Climate in Ko Samui in October
| September | October | November | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +81°F | +79°F | +79°F | ||||
| Min. temperature | ||||||
| +70°F | +70°F | +66°F | ||||
| Max. temperature | ||||||
| +90°F | +90°F | +86°F | ||||
| Rainfall | ||||||
| 142 mm | 242 mm | 278 mm | ||||
| Wind | ||||||
| 3 m/s | 2 m/s | 3 m/s | ||||
| Avg. water temperature | ||||||
| +84°F | +85°F | +85°F | ||||
| Humidity | ||||||
| 79% | 82% | 82% | ||||
| Air pressure | ||||||
| 1008 HPa | 1009 HPa | 1010 HPa | ||||
| Sunny days | ||||||
| 0 | 0 | 1 | ||||
| Cloudy days | ||||||
| 2 | 2 | 3 | ||||
| Rainy days | ||||||
| 17 | 16 | 17 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
October weather is still as ok as in September. It’s getting colder in October. From +81°F in the day, the average maximum temperature lowers to +79°F. Prepare for more rain. Average rainfall goes from 142 mm to 242 mm. Humidity rises from 79% to 82%. Winds are calmer in comparison to September, going down from 3 m/s to 2 m/s on average. The amount of sunny days stay about the same, averaging 0 sunny days during the month.
November brings much the same weather, it remains ok.
Wind
The average wind speed is 2 m/s getting up to 4 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Ko Samui is gradually increasing during October, going from 3 m/s to 3 m/s over the course of the month.
Rain
How was the weather last October in Ko Samui?
Climate Change Over the Years
The climate in Ko Samui in October has not changed that much over the last 43 years.
The average temperature was the lowest in 1986 (+79°F) and the highest in 2012 (+83°F). The driest year was 1997 with only 927 mm of rainfall, and the wettest year was 1999 with 1981 mm.
FAQ
Is October a good time to visit Ko Samui?
Can you sunbathe in Ko Samui in October?
Can you swim in Ko Samui in October?
Is Ko Samui rainy in October?
Is it sunny in Ko Samui in October?
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.