Thailand Koh Samui Weather in October — Climate Guide
October in Koh Samui is low
Koh Samui Weather in October — Quick Answer
As of 2026- Avg temp
- 30° / 24°
- Rainfall
- 290mm · 19 days
- Crowds
- Quiet
As of 2026, Koh Samui in October averages a high of 30°C and low of 24°C with 290mm of rain over about 19 days. Wet season ramping up — warm but increasingly rainy. Around 30°C/24°C, very humid. Light clothing plus a proper rain jacket and umbrella; quick-dry fabrics help. Sea ~29°C and getting choppier.
October is low for Koh Samui.
October is when Koh Samui's wet season takes hold, averaging 30°C/24°C with high rainfall (around 290mm over roughly 19 wet days) as the northeast monsoon begins influencing the Gulf coast.
Rain becomes frequent and sometimes heavy, seas grow choppier, and boat trips to Ang Thong, Koh Phangan, and Koh Tao are often canceled. It's the cheapest time of year, with deep hotel discounts and very few crowds, but it's a real gamble for a beach-and-boat holiday.
Travel score
Koh Samui October Weather Stats
Avg High
30°C
Avg Low
24°C
Rainy Days
19
290mm total
Sunshine
5h
Daily avg
Humidity
84%
muggy
UV Index
9
Very high
Wind
14 km/h
Gusts 28
Sea Temp
29°C
Avg water temp
Crowds
Quiet
At attractions
October Sunrise & Sunset
Air Quality
PM2.5
13 μg/m³
PM10
24 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
36°C
Nighttime
26°C
Humidity and wind affect how the actual temperature feels.
Wind
14 km/h
Max gust 28 km/h
Activities Recommended for October
October Travel Pros & Cons
Pros
- Lowest prices of the year — deep discounts
- Very few crowds
- Rain often in bursts, not all day
- Lush, green landscapes
Cons
- Wet season — high rainfall (~290mm)
- Boat trips frequently canceled (rough seas)
- Very humid, less sunshine
- Andaman coast is the better bet now
October Events & Festivals
- Wet season ramping up toward the November peak
- Lowest prices of the year — deep discounts
- Boat trips frequently canceled (rough seas)
- Vegetarian Festival (date varies) at some temples
Koh Samui in October — Full Picture
October is when Koh Samui's wet season takes hold, averaging 30°C/24°C with high rainfall (around 290mm over roughly 19 wet days) as the northeast monsoon begins influencing the Gulf coast.
Rain becomes frequent and sometimes heavy, seas grow choppier, and boat trips to Ang Thong, Koh Phangan, and Koh Tao are often canceled. It's the cheapest time of year, with deep hotel discounts and very few crowds, but it's a real gamble for a beach-and-boat holiday.
That said, rain often comes in intense bursts rather than all day, so a flexible trip focused on resort time, spa, and food can still work — just keep boat trips loosely planned and have indoor backups.
Note the Gulf timing once more: as Samui slides into its wettest stretch, the Andaman coast (Phuket/Krabi) is moving into its best season — so a switch of coast is worth considering for an October trip.
The sea stays warm (~29°C) but visibility and calm decline. UV is still high (9) between showers.
What to Wear & What to Pack
Wet season ramping up — warm but increasingly rainy. Around 30°C/24°C, very humid. Light clothing plus a proper rain jacket and umbrella; quick-dry fabrics help. Sea ~29°C and getting choppier.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
31.7°C
25°C
10/mo
Summer (Jun·Jul·Aug)
32°C
25°C
13.3/mo
Autumn (Sep·Oct·Nov)
Current30°C
24.3°C
18/mo
Winter (Dec·Jan·Feb)
29°C
24°C
12.3/mo
Koh Samui Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 29° | 24° | 14d·180mm | 6.5h | 82% | 10 | Very busy | Peak | |
| February (Best) | 30° | 24° | 6d·60mm | 8h | 78% | 11 | Very busy | Peak |
| March (Best) | 31° | 25° | 7d·75mm | 8.5h | 78% | 12 | Busy | Peak |
| 32° | 25° | 9d·100mm | 8.5h | 78% | 12 | Busy | Peak | |
| 32° | 25° | 14d·150mm | 7h | 80% | 11 | Moderate | Shoulder | |
| 32° | 25° | 13d·110mm | 7.5h | 78% | 11 | Busy | Shoulder | |
| 32° | 25° | 13d·110mm | 7.5h | 78% | 11 | Very busy | Peak | |
| 32° | 25° | 14d·110mm | 7h | 78% | 11 | Very busy | Peak | |
| 31° | 25° | 15d·150mm | 6h | 80% | 10 | Moderate | Shoulder | |
| 30° | 24° | 19d·290mm | 5h | 84% | 9 | Quiet | Low season | |
| 29° | 24° | 20d·340mm | 4.5h | 85% | 9 | Quiet | Low season | |
| 28° | 24° | 17d·230mm | 5h | 84% | 9 | Very busy | Peak |
View Other Months
Koh Samui October Hotel Picks
Frequently Asked Questions
Is October a good time to visit Koh Samui?
Koh Samui in October is low. Tourist crowds are quiet and flight/hotel prices are low season.
What's the average temperature in Koh Samui in October?
Koh Samui October averages a high of 30°C and a low of 24°C.
Does it rain much in Koh Samui in October?
Koh Samui October averages 290mm of rainfall over about 19 rainy days.
What should I wear in Koh Samui in October?
Wet season ramping up — warm but increasingly rainy. Around 30°C/24°C, very humid. Light clothing plus a proper rain jacket and umbrella; quick-dry fabrics help. Sea ~29°C and getting choppier.
What time are sunrise and sunset in Koh Samui in October?
Koh Samui October sunrise is 06:00 and sunset is 18:10, with 12h 10min of daylight.
What's the air quality like in Koh Samui in October?
Koh Samui October air quality (AQI) averages 36, rated Good. PM2.5 averages 13μg/m³.
What activities are recommended in Koh Samui in October?
In October, Koh Samui is great for Resort & spa days, Fisherman's Village dining, Island temple loop (between showers).
Is October peak season in Koh Samui?
Koh Samui October crowds are quiet and prices are low season. You can travel relatively comfortably without long queues.
Best Months to Visit Koh Samui
View Other Months
Planning a October trip to Koh Samui?
You've checked the weather — next come the budget and the route.
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.