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Ko Samui in December: Weather, Average temperature and Climate

Take a look at past year’s weather for Ko Samui in December and see if it is worth visiting.
Check flight prices to Ko Samui on Avionero:
December

Weather in Ko Samui in December 2024

OK Weather
Warm
🌧️
Rainy
🌊
Very warm water
Ko Samui in December usually sees fair weather conditions, with an average daily high temperature of +79°F and roughly 2 sunny days. However, you should prepare for about 16 rainy days with an average precipitation of 115 mm. The weather is changeable so pack for every eventuality. Search flights in one click on Avionero.

Average weather

☀️
+79°F
Avg. max. temperature
+68°F
Min.
+86°F
Max.
115 mm
Total precipitation
79%
Avg. humidity
3 m/s
Avg. wind
2 ☀️
Sunny Days
10 ⛅️
Cloudy
16 🌦
Rainy
Our opinion: Ko Samui has OK weather in December.

Average temperature in Ko Samui in December

Here are the expected maximum, average and minimum temperatures in Ko Samui for December based on the historical data.
Last Year
Historical Data

The temperature in December is +79°F on average, with a range between a maximum of +81°F during the day and a minimum of +73°F at night.

The average maximum temperature goes up 50% by the end of the month, compared with the beginning of the month, from +77°F to +81°F.

Is Ko Samui warm or cold in December?

Ko Samui is typically warm in December.

Maximum temperatures go up compared to the previous month from +79°F to +79°F. The minimum temperature also goes up from +75°F to +75°F.

It’s generally warm, but pack a long-sleeve shirt for evenings.

Take a look at how December is compared to other months in Ko Samui:

Water temperature in Ko Samui in December

Water in Ko Samui in December is Very warm. It varies from +80°F to +85°F, with an average of +83°F. Note that the air temperature is lower than the water temperature, averaging around +79°F.

The water temperature in December is one of the coldest of the entire year:

The warmest water temperatures in Ko Samui are reached in May, when the average sea temperature rises to +86°F. The coldest water temperatures are in January, with an average of +82°F.

Can you swim in Ko Samui in December?

You can definitely swim in Ko Samui in December, the water is very warm (+83°F in average), and might even be unpleasant for ones who like it more fresh.
🦭
Cold
Below +61°F
🏄‍♂️
Fresh
61°F - 70°F
🏊
Comfortable
70°F - 77°F
👙
Warm
77°F - 82°F
🔥
Very warm
+82°C and up
Don't forget sunscreen and a hat, it's going to be hot!

Climate in Ko Samui in December

Ko Samui weather looks like this, on average, in December and the surrounding months.
NovemberDecemberJanuary
Avg. temperature
+79°F+79°F+77°F
Min. temperature
+66°F+68°F+64°F
Max. temperature
+86°F+86°F+86°F
Rainfall
278 mm115 mm47 mm
Wind
3 m/s3 m/s3 m/s
Avg. water temperature
+85°F+83°F+82°F
Humidity
82%79%79%
Air pressure
1010 HPa1011 HPa1011 HPa
Sunny days
123
Cloudy days
31011
Rainy days
171616
Snowy days
000

December weather is still as ok as in November. The temperature levels stay the same in the area of +79°F for average maximum temperature during the day. As December arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 278 mm to 115 mm. It feels drier, as humidity decreases from 82% to 79%. The average wind speed doesn’t change much during December, staying around 3 m/s. The good news is there are likely to be more sunny days in December, from 1 to 2.

But maybe it is worth considering traveling in January as the weather gets better.

Wind

Wind speed in Ko Samui in December based on historical data.
Last Year
Historical Data

The average wind speed is 3 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.

The average wind speed in Ko Samui is gradually increasing during December, going from 2 m/s to 2 m/s over the course of the month.

Rain

Amount of rainfall in mm during December in Ko Samui based on historical data.
Last Year
Historical Data
A chance of rain on a typical day in December stands at 65%, leading to total precipitation of around 84 mm. The maximum amount of rainfall per day is around 20 mm, which is considered light rain. December is a pretty wet month with over 20 rainy days, so don’t forget to pack an umbrella, raincoat, and a pair of wellies.
Here’s how December is compared with other months in the amount of precipitation, total mm:
Ko Samui wettest month is November, where a typical day has a 57% chance of precipitation and 278 mm of rainfall per day. February, on the other hand, is the driest month with a mere 38% chance of precipitation and 29 mm of rainfall per day.

How was the weather last December in Ko Samui?

This is the weather in Ko Samui in December 2023:
1 December
🌧️
+78°F
2 December
🌧️
+78°F
3 December
🌧️
+78°F
4 December
🌧️
+78°F
5 December
🌧️
+77°F
6 December
☁️
+79°F
7 December
🌧️
+78°F
8 December
☁️
+79°F
9 December
☀️
+80°F
10 December
☀️
+79°F
11 December
☀️
+80°F
12 December
☀️
+80°F
13 December
☀️
+79°F
14 December
☀️
+81°F
15 December
☀️
+81°F
16 December
☀️
+80°F
17 December
🌧️
+78°F
18 December
☀️
+80°F
19 December
☁️
+80°F
20 December
☀️
+81°F
21 December
🌧️
+79°F
22 December
☀️
+79°F
23 December
☁️
+77°F
24 December
🌧️
+77°F
25 December
☁️
+77°F
26 December
☀️
+79°F
27 December
☀️
+79°F
28 December
☀️
+80°F
29 December
☀️
+79°F
30 December
☁️
+79°F
31 December
☀️
+80°F
In December 2023 Ko Samui had 16 sunny days, 6 cloudy days, and 9 rainy days. The average maximum temperature was +79°F, with an absolute maximum of +81°F and a minimum of +77°F. The average humidity was 81%, with a maximum of 92% and a minimum of 71%. The average wind speed was 3 m/s, with a maximum of 10 m/s and a minimum of 0 m/s.
Are you planning a trip in December?

Climate Change Over the Years

This is how Ko Samui climate has changed over the last 43 years.

The climate in Ko Samui in December has not changed that much over the last 43 years.

The average temperature was the lowest in 1986 (+79°F) and the highest in 2012 (+83°F). The driest year was 1997 with only 927 mm of rainfall, and the wettest year was 1999 with 1981 mm.

FAQ

Frequently asked questions about the weather in Ko Samui in December:

Is December a good time to visit Ko Samui?

It’s always a good time to visit Ko Samui, but the weather is changeable in December, so plan a mix of indoor and outdoor activities and exploring, and pack for every eventuality.

Can you sunbathe in Ko Samui in December?

December is warm in Ko Samui. You may enjoy some beach or pool time in the day, but pack something a tad warmer for the evening.

Can you swim in Ko Samui in December?

Yes, you can swim in Ko Samui in December, the water is very warm, with temperature averaging at +83°F, but it's important to manage hydration and sun exposure.

Is Ko Samui rainy in December?

Ko Samui is often rainy in December. You may get a bit damp when outside, so pack an umbrella, and maybe even a raincoat.

Is it sunny in Ko Samui in December?

Usually, it’s not very sunny in Ko Samui in December, often it’s pretty cloudy. Pack for any eventuality; layering can help reduce the number of bulky items needed.

Other cities in Thailand

Check out the weather for other cities in Thailand.

Monthly weather in Ko Samui

Source of the data

For this page, we’ve looked at the typical weather in Ko Samui, based on historical hourly weather data from January 1, 1979, to December 31, 2023.

For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.