Thailand Koh Samui Weather in July — Climate Guide
July in Koh Samui is high
Koh Samui Weather in July — Quick Answer
As of 2026- Avg temp
- 32° / 25°
- Rainfall
- 110mm · 13 days
- Crowds
- Very busy
As of 2026, Koh Samui in July averages a high of 32°C and low of 25°C with 110mm of rain over about 13 days. Drier mid-year spell continues — warm and often sunny. Around 32°C/25°C. Light clothing, swimwear, SPF 50+, and a light rain layer for brief showers. Sea ~30°C.
July is high for Koh Samui.
July sits in the heart of Koh Samui's drier mid-year window, averaging 32°C/25°C with modest rainfall (around 110mm), usually as short showers. It's one of the most reliable times to visit weather-wise outside the main dry season.
Sunny days and calm seas make Ang Thong, Koh Phangan, and Koh Tao trips dependable, with good diving and snorkeling. This is European summer-holiday high season, so beaches in Chaweng and Bophut are busy and prices climb toward peak levels — book ahead.
Travel score
Koh Samui July Weather Stats
Avg High
32°C
Avg Low
25°C
Rainy Days
13
110mm total
Sunshine
7.5h
Daily avg
Humidity
78%
muggy
UV Index
11
Extreme
Wind
12 km/h
Gusts 22
Sea Temp
30°C
Avg water temp
Crowds
Very busy
At attractions
July Sunrise & Sunset
Air Quality
PM2.5
14 μg/m³
PM10
25 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
38°C
Nighttime
27°C
Humidity and wind affect how the actual temperature feels.
Wind
12 km/h
Max gust 22 km/h
Activities Recommended for July
July Travel Pros & Cons
Pros
- Peak of the reliable mid-year window
- Sunny days and calm seas for boat trips
- Great diving and snorkeling conditions
- Opposite of the rainy Andaman coast
Cons
- European summer high season — busy and pricier
- Brief showers still possible
- High humidity
- Alcohol curbs on some Buddhist holidays
July Events & Festivals
- Peak of the drier mid-year window (Jun-Aug)
- European summer-holiday high season
- Good, reliable boat-trip conditions
- Asanha Bucha & Buddhist Lent (dates vary) — alcohol sales restricted some days
Koh Samui in July — Full Picture
July sits in the heart of Koh Samui's drier mid-year window, averaging 32°C/25°C with modest rainfall (around 110mm), usually as short showers. It's one of the most reliable times to visit weather-wise outside the main dry season.
Sunny days and calm seas make Ang Thong, Koh Phangan, and Koh Tao trips dependable, with good diving and snorkeling. This is European summer-holiday high season, so beaches in Chaweng and Bophut are busy and prices climb toward peak levels — book ahead.
Buddhist holidays such as Asanha Bucha and the start of Buddhist Lent (Khao Phansa) fall around July (dates vary by year); on these days some shops restrict alcohol sales, so plan around it if that matters.
The sea is warm (~30°C). UV remains high (11).
The Gulf timing continues to favor Samui: it's enjoying fine mid-year weather while the Andaman coast is at its wettest — a key reason July is popular here.
What to Wear & What to Pack
Drier mid-year spell continues — warm and often sunny. Around 32°C/25°C. Light clothing, swimwear, SPF 50+, and a light rain layer for brief showers. Sea ~30°C.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
31.7°C
25°C
10/mo
Summer (Jun·Jul·Aug)
Current32°C
25°C
13.3/mo
Autumn (Sep·Oct·Nov)
30°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 July Hotel Picks
Frequently Asked Questions
Is July a good time to visit Koh Samui?
Koh Samui in July is high. Tourist crowds are very busy and flight/hotel prices are peak.
What's the average temperature in Koh Samui in July?
Koh Samui July averages a high of 32°C and a low of 25°C.
Does it rain much in Koh Samui in July?
Koh Samui July averages 110mm of rainfall over about 13 rainy days.
What should I wear in Koh Samui in July?
Drier mid-year spell continues — warm and often sunny. Around 32°C/25°C. Light clothing, swimwear, SPF 50+, and a light rain layer for brief showers. Sea ~30°C.
What time are sunrise and sunset in Koh Samui in July?
Koh Samui July sunrise is 06:05 and sunset is 18:40, with 12h 35min of daylight.
What's the air quality like in Koh Samui in July?
Koh Samui July air quality (AQI) averages 37, rated Good. PM2.5 averages 14μg/m³.
What activities are recommended in Koh Samui in July?
In July, Koh Samui is great for Ang Thong Marine Park (good conditions), Koh Tao diving & snorkeling, Koh Phangan beaches & Full Moon Party.
Is July peak season in Koh Samui?
Koh Samui July crowds are very busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Koh Samui
View Other Months
Planning a July 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.