Thailand Koh Samui Weather in March — Climate Guide
March in Koh Samui is very-high
Koh Samui Weather in March — Quick Answer
As of 2026- Avg temp
- 31° / 25°
- Rainfall
- 75mm · 7 days
- Crowds
- Busy
As of 2026, Koh Samui in March averages a high of 31°C and low of 25°C with 75mm of rain over about 7 days. Hot, dry, and sunny — peak dry season continues. Around 31°C/25°C with low rainfall. Light clothing, swimwear, a hat, and SPF 50+ are essential under extreme UV. Stay hydrated. Sea ~29°C.
March is very-high for Koh Samui.
March is another of Koh Samui's best months — dry, sunny, and hot, with low rainfall (around 75mm). It averages 31°C/25°C, a touch warmer than February.
Seas stay calm and clear, so Ang Thong, Koh Phangan, and Koh Tao trips are reliable with great snorkeling and diving. This is the heart of the dry window (mid-January to April) and a strong all-round month for beaches and island-hopping.
Travel score
Koh Samui March Weather Stats
Avg High
31°C
Avg Low
25°C
Rainy Days
7
75mm total
Sunshine
8.5h
Daily avg
Humidity
78%
comfortable
UV Index
12
Extreme
Wind
12 km/h
Gusts 22
Sea Temp
29°C
Avg water temp
Crowds
Busy
At attractions
March Sunrise & Sunset
Air Quality
PM2.5
15 μg/m³
PM10
28 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
36°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 March
March Travel Pros & Cons
Pros
- Excellent dry-season weather — low rainfall
- Calm, clear seas — great diving and snorkeling
- Mango season begins (best mango sticky rice)
- Strong all-round beach and island-hopping month
Cons
- High season prices and crowds
- Extreme UV (12) and building heat
- Midday sun is intense — hydrate and shade
March Events & Festivals
- Peak dry season continues — excellent weather
- Calm, clear seas — prime boat-trip conditions
- Mango season begins (great mango sticky rice)
- Building heat ahead of April
Koh Samui in March — Full Picture
March is another of Koh Samui's best months — dry, sunny, and hot, with low rainfall (around 75mm). It averages 31°C/25°C, a touch warmer than February.
Seas stay calm and clear, so Ang Thong, Koh Phangan, and Koh Tao trips are reliable with great snorkeling and diving. This is the heart of the dry window (mid-January to April) and a strong all-round month for beaches and island-hopping.
Mango season gets going — the mango sticky rice is at its best now through June. It's still peak season, so prices and crowds are high, though slightly past the February-Chinese New Year peak.
The heat is building toward April's hottest stretch, and UV is extreme (12) — limit midday sun, hydrate, and reapply SPF 50+. The sea is a warm ~29°C with excellent clarity.
As with the rest of the dry season, both Samui (Gulf) and the Andaman coast are good now, so it's a flexible month for combining Thai destinations.
What to Wear & What to Pack
Hot, dry, and sunny — peak dry season continues. Around 31°C/25°C with low rainfall. Light clothing, swimwear, a hat, and SPF 50+ are essential under extreme UV. Stay hydrated. Sea ~29°C.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
Current31.7°C
25°C
10/mo
Summer (Jun·Jul·Aug)
32°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 March Hotel Picks
Frequently Asked Questions
Is March a good time to visit Koh Samui?
Koh Samui in March is very-high. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in Koh Samui in March?
Koh Samui March averages a high of 31°C and a low of 25°C.
Does it rain much in Koh Samui in March?
Koh Samui March averages 75mm of rainfall over about 7 rainy days.
What should I wear in Koh Samui in March?
Hot, dry, and sunny — peak dry season continues. Around 31°C/25°C with low rainfall. Light clothing, swimwear, a hat, and SPF 50+ are essential under extreme UV. Stay hydrated. Sea ~29°C.
What time are sunrise and sunset in Koh Samui in March?
Koh Samui March sunrise is 06:15 and sunset is 18:25, with 12h 10min of daylight.
What's the air quality like in Koh Samui in March?
Koh Samui March air quality (AQI) averages 40, rated Good. PM2.5 averages 15μg/m³.
What activities are recommended in Koh Samui in March?
In March, Koh Samui is great for Ang Thong Marine Park (prime conditions), Koh Tao diving & snorkeling, Beach days + mango sticky rice.
Is March peak season in Koh Samui?
Koh Samui March crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Koh Samui
View Other Months
Planning a March 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.