Koh Samui in April

In April, Koh Samui averages 31°C (87°F) during the day and 27°C (80°F) at night, with frequent rain — about 23 days of the month see precipitation (107 mm total).

Shoulder

Conditions are warm and beach-friendly. Expect daily rain or showers, often in heavy bursts.

April is one of the wetter and less comfortable months in Koh Samui. If your dates are flexible, consider a different time of year.

31°C
Avg high
27°C
Avg low
23
Rain days
107 mm
Rainfall

How April compares to the rest of the year in Koh Samui

1st
warmest month of the 12
10th
wettest month of the 12
7%
of yearly rainfall falls in April
12 h 20 min
daylight on the 15th

April is one of the warmest months in Koh Samui (1st of 12) and one of the driest months (10th of 12). Daytime temperature runs 1°C above the annual average (29°C). April runs 1°C warmer than March (30°C) and stays flat into May.

April sunrise & sunset in Koh Samui

🌅
Sunrise (15th)
6:10 AM
🌇
Sunset (15th)
6:29 PM
Day length
12 h 20 min

Times shown for Koh Samui local time (Asia/Bangkok), calculated for the 15th of April. They shift by a few minutes day to day across the month.

Photography light in Koh Samui — April

Golden-hour and blue-hour windows for the 15th of April, in Koh Samui's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
5:10 AM – 5:50 AM
🌄 Golden hour (AM)
5:50 AM – 6:50 AM
🌇 Golden hour (PM)
5:49 PM – 6:49 PM
🌆 Blue hour (PM)
6:49 PM – 7:29 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near Koh Samui.

📅 When to book — Koh Samui in April

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on April's tier (Shoulder) and Koh Samui's popularity.

✈ Flights — lead time
6-10 weeks
Sweet spot for value. Major fare-sales (US: Black Friday, EU: post-Easter) hit hardest in shoulder months for shoulder travel.
🏨 Lodging — lead time
4-8 weeks
Lots of selection. Look for shoulder-season packages — many hotels add value (free breakfast, spa credit) to fill rooms.

April in Thailand — events that affect travel

Known cultural, religious, or national events that surge prices, fill hotels, or close businesses during this month. Plan around them, or build your itinerary around the ones you'd like to see.

🇹🇭
Songkran (Thai New Year)
Festival · medium impact

The world's biggest water fight — three days of street-wide water battles in every Thai city. Hotels in Bangkok and Chiang Mai book solid; offices and many shops close.

Plan: Bring waterproof phone bags. Either embrace the chaos or stay in a quiet beach resort that's out of the fray.

Crowds & pricing — April in Koh Samui

Shoulder

Koh Samui is in a shoulder season month — fewer crowds, slightly lower prices, and a calmer atmosphere than peak weeks. Most major sights stay open with normal hours, though a handful of seasonal restaurants or boat trips may run reduced schedules. Many regulars consider these months the best time to visit because you trade a small amount of weather reliability for a much more pleasant on-the-ground experience.

Sun & mosquito risk — April in Koh Samui

☀️ UV Index (noon, 15th)
13
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●●●
Severe
Severe mosquito season with active disease transmission risk. DEET 30%+, picaridin 20%, long sleeves day and night, treated nets, and check CDC/WHO travel advisories before going.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Sea temperature in Koh Samui — April

31.7°C (89°F)
bath-warm
tropical and comfortable for hours

Across the year Koh Samui's sea swings from 28.6°C (January) to 32.1°C (May) — April sits at 31.7°C.

Koh Samui in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 28°C / 82°F 25°C / 76°F 113 mm 24
February 28°C / 83°F 25°C / 77°F 33 mm 17
March 30°C / 86°F 26°C / 78°F 32 mm 17
April 31°C / 87°F 27°C / 80°F 107 mm 23
May 31°C / 87°F 27°C / 80°F 130 mm 29
June 30°C / 86°F 27°C / 80°F 96 mm 27
July 30°C / 86°F 26°C / 79°F 115 mm 28
August 30°C / 86°F 26°C / 79°F 94 mm 28
September 29°C / 84°F 26°C / 78°F 172 mm 29
October 28°C / 83°F 25°C / 77°F 234 mm 31
November 28°C / 82°F 25°C / 77°F 274 mm 29
December 28°C / 82°F 25°C / 76°F 182 mm 24

Other cities with similar April weather

🌍 See the full ranked list of climate twins for Koh Samui in April →

Frequently asked questions

How hot is Koh Samui in April?

In April, Koh Samui averages a high of 31°C (87°F) and a low of 27°C (80°F) — generally hot.

Does it rain a lot in Koh Samui in April?

April is quite rainy in Koh Samui, with about 23 rainy days on average.

Is April a good time to visit Koh Samui?

April is hot but on the rainy side. It suits travelers who are comfortable with hot weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Koh Samui in April?

Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full April packing list for Koh Samui for a complete, climate-based checklist.

Open Koh Samui on the interactive map

Check the live 10-day forecast and sunrise/sunset.