Koh Samui weather in December

December sees the end of the wet season and the start of the dry season.

You can expect warm and sunny days interspersed with occasional short bursts of heavy rainfall that gradually lessen from the middle of December onwards. Daytime temperatures are slightly cooler averaging 27°C (80°F).

December also brings strong winds that can make the east side of Koh Samui rough for swimming.

How hot is it in Koh Samui in December?
Daytime temperatures in Koh Samui in December reach an average high of 30°C (86°F) with high heat and humidity, falling to a night-time low of 26°C (78°F).

How sunny is it in Koh Samui in December?
There are normally six hours of bright sunshine each day in Koh Samui in December – that's around 54% of daylight hours.

Sunrise & sunset in December?
Sunrise is around 6:25am with sunset around 6:00pm.

How warm is the sea around Koh Samui in December?
The average sea temperature in Koh Samui in December is 29°C (84°F).

Does it rain in Koh Samui in December?
There are usually 11 days with some rain in Koh Samui in December; the average monthly rainfall is 332mm (11in).

How windy is it in Koh Samui in December?
December sees an average hourly wind speed of 19 kilometres per hour (12 mph; 10 knots).

What to do in Koh Samui in December?
Windy weather conditions in December are not so good for swimming, snorkelling, scuba diving and kayaking.

Typically, wind conditions on the west coast are better for swimming while the east coast is best for wind surfing.

Local holidays?
Father's Day – 5th Dec; H.M. King Bhumibol Adulyadej The Great’s Birthday – 5th Dec; Constitution Day – 12th Dec; New Year's Eve – 31st Dec.

From mid-December onward is high season in Koh Samui, with higher hotel prices and the need to book early, especially during Christmas and the New Year holiday period.

Koh Samui weather in December

Temperature icon High Temp: 30°C (86°F)
temperature icon Low Temp: 26°C (78°F)
sun icon Sunshine: 6 hours per day
Moderately hot icon
Daylight: 12 hours per day
wind icon Wind speed: 19 km/h (12 mph; 10 knots)
umbrella icon Wet Days: 11 days with some rain
rain cloud Rainfall: 332 mm (13 in) per month
High heat icon Comfort Level: High heat & 84% humidity
Moderately hot icon
UV Index: High
swimming icon Sea Temp: 29°C (84°F)
Koh Samui, Thailand

Best time to visit Koh Samui

The best time to visit Koh Samui is during January and February.

However, anytime during the dry season from mid-December through to early-March is good, with daytime temperatures averaging 28°C (82°F).

For more climate info: Koh Samui weather overview

Koh Samui weather by month

Source: Meteorological data for Koh Samui is based on weather statistics gathered for the 10-year period 2012 to 2021 by the Thai Meteorological Department at the closest weather station: Koh Samui Airport, (USM), located about 2km north of Chaweng.

Advice on the best time to visit a particular destination is based on average local weather statistics, when the weather conditions are generally better than at other times of the year. We consider high and low temperatures, risk of rain (and thunderstorms, etc.), amount of sunshine and sea temperature. For general outdoor activities we favour clear, rainless days with a temperature range between 18°C (64°F) and 27°C (80°F); and for hot-weather activities we favour clear, rainless days with a temperature range between 24°C (75°F) and 32°C (89°F). Often, the best times to visit correspond to high season and therefore involve higher prices.

Latest update: Koh Samui weather in April: 12 June, 2024

Disclaimer: The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data and conditions at any given location and time are unpredictable and variable. We assume no responsibility and can not be held legally responsible for any decisions made on the basis of the information presented on this site.