The Ultimate Guide to Koh Samui Weather

Koh Samui Island is located in Surat Thani province, which is off the coast of East Kra Isthmus in Thailand. Before planning a trip, follow our travel guide to the featured characteristics of Koh Samui weather.

Koh Samui has a tropical climate and is warm all year-round. Each month, the weather in Koh Samui brings a different feeling and makes a sense of interest for anyone coming here. So, let’s read the essential guide to Koh Samui weather to understand the weather of each month.

What is the weather like in Koh Samui?

The climate in Koh Samui experiences an average temperature of 28 - 32°C. It is not affected by the south-west monsoon like the majority of Thailand, so it's a better option for warm and dry weather than Phuket and Khao Lak. Instead, it has its own rainy season between October and December. It offers all that vacationers from cooler temperate countries could dream of regarding weather conditions. They are generally good year-round, and the one thing you will rarely feel here is cold. You can enjoy the optimum weather conditions between December and August.
Now let’s find out the Koh Samui weather each month.

Koh Samui

1. Koh Samui weather in January

January is warm and dry on Koh Island. Has an average temperature of about 26°C and 7 hours of sunshine daily. January is the peak season in Thailand because the weather across the country is great, so it's a good time to combine Koh Samui with a stop in Bangkok and visit the beautiful cities of Chiang Mai and Chiang Rai in Northern Thailand.

2. Koh Samui weather in February

The Koh Samui weather in February has a lovely dry and warm climate with the minimum expected rainfall. There are 8 hours of sunshine a day and a warm sea temperature of about 27°C, making it one of the best months to sunbathe and enjoy Koh Koh's white-sand beaches.

3. Koh Samui weather in March

March is a great month to visit Koh Samui when the weather is warm and dry and the days are often filled with blue skies. The average temperature is between 26-31°C and has 8 hours of sunshine per day.

4. Koh Samui weather in April

Hot and humid day in Koh Samui in April. This is one of the hottest months in Koh Samui as well as the rest of Thailand, with an average temperature of 27°C to 33°C. There are 8 hours of sunshine a day and the sea is warm at around 28°C.

5. Koh Samui weather in May

The weather in Koh Samui is hot and sunny in May with some rain. The day is likely hot and dry with regular showers. The average temperature is around 26 - 33°C and there are about 7 hours of sunshine per day.

6. Koh Samui weather in June

June is a great month to visit Koh Samui, where there are light rain and hot and sunny days. As conditions became increasingly wet around the rest of Thailand, it remained dry with an average temperature of 29°C and warm sea at about 28°C.

Enjoying the great weather in Koh Samui

7. Koh Samui weather in July

Koh Samui's climate is warm and mostly dry in July - the best option in Thailand during summer vacation as other parts of Thailand will have a chance of heavy rain. The average temperature is around 29°C and has 6 hours of sunshine per day. There may be some rainfall, although this usually happens shortly, heavy rain tends to clear quickly.

8. Koh Samui weather in August

August is a good month to visit Koh Samui during the school's summer holiday. The rest of the country is likely to have high rainfall, so for beaches and warm weather, it is a much better option if you are visiting Thailand. There, the average temperature is 29°C and the warm sea temperature is 28°C.

9. Koh Samui weather in September

September is warm in Koh Samui with moderate rainfall. As the rainy season of Koh Samui approaches, you can expect more rain than the previous months. It brings more frequent showers and often tends to be interspersed with sunny days. Koh Samui is significantly quieter in September when the school holidays are over, so this might be a good time to take advantage of the smaller quantities and great deals.

10. Koh Samui weather in October

October is warm, moist, and humid in Koh Samui. Because the Gulf of Thailand is affected by the northeast monsoon, there is a high probability of precipitation during the month and the sea conditions can be very difficult. If you don't have a relaxing mind in your resort while it rains, you can still enjoy the warmth with average temperatures to find some of Koh Samui's most valuable deals, during the low season. If you travel in October but want lots of sunshine, we recommend going to the beach in a hot place and with much lower rainfall.

11. Koh Samui weather in November

The weather in Koh Samui is humid and humid in November. The weather is still warm with an average temperature of 27°C and there may be lots of rain and thunderstorms throughout the month. For a higher chance of sunshine and better sea conditions, Phuket and Khao Lak on the Andaman coast have drier and more sunny weather in November.
Loy Krathong Festival takes place on the night of the full moon in November. This is a celebration where people can let go of negative emotions by floating symbolic Krathong, traditional small gifts made from banana leaves, and dropping lanterns to the sky.

12. Koh Samui weather in December

Koh Samui is warm and humid in December with a reasonable chance of rain. The average temperature is 27°C and you can expect showers when the rainy season in Koh Samui, the rainy season starts to subside. Phuket and Khao Lak on the Andaman coast are better options for sunny weather.

Exploring Koh Samui by bicycle

Above is the ultimate guide to the weather in Koh Samui throughout the year. No matter what is limited, it is still a worthwhile place to visit. Choosing the best time to visit Koh Samui, you can not miss and should prepare a meaningful trip here.

Jenny Tran

(Image source: Internet)