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The Ultimate Guide to Weather on Koh Samui

Koh Samui's climate has many weather patterns and seasons during the year, and will be an important part to planning your trip. In this guide, we will provide you with everything you need to know about the weather on Koh Samui, ensuring that you have the best experience possible!


Understanding Koh Samui's Climate

Koh Samui is located in the Gulf of Thailand and has a tropical monsoon climate. The weather is generally warm and humid throughout the year, with two distinct seasons: the dry season and the rainy season.


Dry Season (December to February)

The dry season is considered the peak tourist season in Koh Samui, due to its favorable weather conditions. During this time, the island experiences clear skies, ample sunshine, and less rainfall. The average temperature ranges between 24°C (75°F) and 31°C (88°F), making it an ideal time for beach activities, snorkeling, and exploring the island's natural beauty.


Rainy Season (March to November)

The rainy season on Koh Samui is characterized by frequent showers and higher humidity levels. However, the rainfall is often in short bursts and typically occurs in the late afternoon or evening. Despite the rain, there are still plenty of activities to enjoy on the island, such as visiting waterfalls, exploring indoor attractions, or indulging in wellness retreats. The average temperature during the rainy season ranges between 25°C (77°F) and 30°C (86°F).


To help you plan your trip, here is a month-by-month break down on typical weather conditions on the island:


March marks the beginning of the rainy season on Koh Samui. While the island experiences occasional showers, the weather remains relatively warm and pleasant. The average temperature hovers around 27°C (81°F).


April is known for its high temperatures and increased humidity. This month experiences a mix of sunny days and short rain showers. The average temperature ranges between 27°C (81°F) and 29°C (84°F).


May is considered one of the hottest months on Koh Samui. The average temperature reaches its peak, ranging from 28°C (82°F) to 30°C (86°F). Be prepared for occasional rain showers and high humidity levels.

June to September:

These months fall within the peak of the rainy season, with increased rainfall and occasional thunderstorms. While the showers can be heavy, they are often short-lived. The average temperature ranges between 27°C (81°F) and 29°C (84°F).


October marks the transition period between the rainy season and the dry season. The rainfall decreases gradually, and the weather becomes more pleasant. The average temperature ranges from 27°C (81°F) to 29°C (84°F).


In November, the rainy season subsides, and Koh Samui experiences less rainfall. The weather becomes more stable, making it a good time to visit the island. The average temperature ranges from 26°C (79°F) to 29°C (84°F).

December to February:

These months mark the dry season, with clear skies and minimal rainfall. The weather is excellent for outdoor activities, and the average temperature ranges between 24°C (75°F) and 31°C (88°F).


Planning Your Trip?

Here are a few tips to make the most of your visit:

1. Pack appropriate clothing: Light, breathable fabrics, swimwear, and sunscreen are essentials for the warm weather on Koh Samui. However, it's also advisable to bring a light rain jacket or umbrella during the rainy season.

2. Explore indoor attractions: In case of heavy rain or storms, make a list of indoor attractions such as museums, temples, or wellness centers to visit during your stay.

3. Be flexible with outdoor activities: If you plan outdoor activities during the rainy season, it's recommended to remain flexible with your schedule as rainfall can be unpredictable. Check the weather forecast regularly and plan accordingly.

4. Connect with locals and tour guides: Locals and tour guides can provide valuable insights into current weather conditions and recommend activities suitable for the prevailing weather.

Remember, regardless of the weather, Koh Samui offers a variety of attractions and experiences that can be enjoyed year-round!


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