SeasonScore
Koh Samui, Thailand
Photo: Ssuri · CC BY-SA 3.0

Thailand

Koh Samui in December

🌧️ Northeast monsoon rains

Warm, humid and very wet.

🎒 Pack: compact umbrella or rain jacket · quick-dry fabrics

Best months: Feb (8.3), Jan (8.2), Mar (8.2)

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Why December scores 7.7What goes into the score

How it works
🌡️ 29° / 24°C🌧️ 263 mm💧 dew pt 24°🍃 PM2.5 11
  • Weather comfort6.3
    • ✓Warm (29°C highs / 24°C lows)
    • !Very humid/sticky (dew point 23.7°C)
    • !Wet: ~263 mm rain, ~7 heavy-rain days
  • Air quality9.1
    • ✓Good (within WHO guideline) (PM2.5 ~11 µg/m³)
  • Seasonal hazards9.5
    • !Flood: ~7 heavy-rain days in an average December
  • Safety baseline8.0
    • ·Normal precautions
Compare monthsPut December side by side with another month
DecFeb
Score7.7 Very good8.3 Very good
Season🌧️ Northeast monsoon rains☀️ Dry season
High / low29° / 24°29° / 25°
Rain263 mm64 mm
Humiditydew pt 24°dew pt 23°
PM2.511 µg/m³21 µg/m³

Typical-month data: NASA POWER (MERRA-2 reanalysis) 2015–2024 (modelled, not a forecast). Temperatures: Ko Samui weather-station normals. Rainfall: Ko Samui weather-station normals (national met service).

Holidays & crowdsDecember 2026

Long weekend

There's at least one long weekend. Domestic travel picks up and popular spots get busier over those days.

  • HM King Bhumibol Adulyadej the Great's Birthday 5–7 Dec · 3 days off in a row
  • New Year 31 Dec – 3 Jan · 4 days off in a row

Other public holidays: Constitution Day (10 Dec)

National holidays only; regional holidays and school breaks aren't included. Source: holidays (open-source public-holiday calendar).

Explore Koh SamuiEvents, sights, food & souvenirs

Check event dates locally

Thailand's second-largest island, in the Gulf of Thailand, visited for beaches, resorts, temples and boat trips to the Ang Thong marine park.

Events in December

No major events on our calendar for December.

Coming up later

SongkranEvery year13-15 April every year

Thai New Year, celebrated with water fights in the streets.

Why go: Expect to get soaked; keep phones in waterproof bags.

Where: Island-wide, especially Chaweng

Loy KrathongDate variesThai lunar calendar, usually November

People float candlelit offerings on the water.

Why go: It falls in the rainy season on Samui.

Where: Beaches and temples