The Best Season to Visit Koh Samui: A Detailed Weather Guide

Best Season to Visit Koh Samui

Table of Contents

Spectacular beaches fringed by palm trees; thick, mountainous rainforests; groves of coconut; historical landmarks; posh spas and luxury resorts; great food and drinks. Koh Samui, Thailand’s second largest island, has them all.

About to visit this wonderful tourist destination in the Gulf of Thailand? Finding out the best season Koh Samui is known for before you do so, is a good idea, so we came up with this Koh Samui Weather Guide to give you insights on the island’s weather conditions at any time of the year. We’ll also throw in some tips on what to pack, safety precautions to take, and things to do in Samui. 

Here we go!

Understanding Koh Samui’s Climate

Best time to visit Koh Samui

Koh Samui has a tropical monsoon climate, meaning that the weather is hot or warm, and windy all year round, while the rainy season is long due to the monsoon of Southeast Asia.

Of course, the degree of heat in the weather varies over the course of the year. The hottest period is from April to September when the temperature could go as high as 93 oF, and the coldest is from October to March with temperatures getting as low as 76 oF towards the end of the year. 

So, in terms of average temperatures, Koh Samui hovers between 78 oF and 91 oF. 

The Four Seasons in Koh Samui

Let’s now talk about the island’s different seasons, focusing on weather conditions plus the pros and cons of visiting during each, so you can figure out which is the best season Koh Samui offers tourists.

1. Dry Season (December to February)

When visit Koh Samui

Dry season in Koh Samui is characterized by minimal rainfall (mostly occasional showers), noticeably cooler temperatures, and light winds which result in calm seas; this makes it the favorite visit period for many travelers, and the peak season for most hotels.


  • You can move about without having to worry about rainfall
  • It’s the best time for water sports
  • Beach days are uninterrupted and lengthy


  • Tourist spots are usually crowded as it’s peak season
  • Accommodation and other prices are higher

2. Hot Season (March to May)

At this time of the year in Samui, the weather is still somewhat dry, but the temperature is no longer as cool as in the preceding dry season months; rather, as the name of the season suggests, it’s significantly hot with lots of sunlight. 


  • Low threat of rainfall
  • Ideal period for those who love to relax in the sun


  • The hot weather can bring discomfort, especially at midday when the sun is most intense
  • Mosquitoes usually become a bit more active

3. Rainy Season (June to September)

best season to visit Koh Samui

During Koh Samui’s rainy season, frequent showers are experienced throughout the day; these vary in intensity, and usually don’t last long. This period of the year is also when the island’s vegetation starts to come into bloom, becoming more green and vibrant.


  • Less crowded spots due to fewer tourists
  • Lower accommodation prices


  • Higher threat of rainfall which could disrupt some outdoor activities

4. Monsoon Season (October to November)

Season to go in Koh Samui

While Ko Samui experiences rainfall most months, the monsoon season is when the rains are heaviest. The weather at this time remains warm and, in addition to heavy rains, light monsoon showers are to be expected. The island is also greenest at this period, with very lush vegetation all around.


  • No crowds
  • It’s the best time for a peaceful retreat as the island is unusually calm
  • Prices are lower


  • Ferry disruptions are more likely
  • Some businesses might close
  • The wet, hot climate increases the threat of mosquitos

Activities to Enjoy in Each Season

At this point in our Koh Samui Weather Guide, a brief discussion of our favorite tourist pastimes is only appropriate. Read on for some of the best activities to enjoy any time you visit Samui.

Koh Samui Dry Season Activities

Which month visit Koh Samui

It’s not for nothing that many tourists like to visit Koh Samui during the dry season. The light winds and calm seas make this period ideal for activities like sailing, snorkeling, diving, windsurfing, and other water sports which you can enjoy at several of the island’s many beautiful beaches. 

The dry season is also a great period for some serious hiking or jungle trekking, and visits to the island’s outdoor attractions if you don’t mind the crowd so much.

Koh Samui Hot Season Activities

Hot season in Koh Samui is not a bad time for water sports; and, thanks to lots of sunny days, you can always sunbathe all you like at the beach, then have a refreshing swim right after. In addition, this period is suitable for island tours and excursions, as well as for attending must-see events such as the popular Songkran festival in April.

Koh Samui Wet & Monsoon Season Activities

Best month visit koh samui

The wet and especially monsoon seasons are not really the best periods to visit a beach or engage in any kind of water sports, due to heavy bursts of rainfall and strong winds. However, there are lots of indoor attractions and places you can visit while it’s raining. Don’t miss the Loy Krathong festival in November.

Safety Tips for Travelers

Our Koh Samui Weather Guide won’t be complete without a word or two regarding preparations and safety. Be sure to pack adequate clothing that matches the weather conditions of the season you intend to visit. If you’re coming during the rainy season, don’t forget your raincoat, umbrella and waterproof bags for your electronic gadgets.

On safety, consider avoiding the hot season altogether, especially April when it’s hottest, if you’re prone to heat stroke or other heat-related health issues. The air conditioning in the hotels can be pretty strong, so a jacket or light sweater should also be part of your wardrobe. Finally, a good insect-repellent is a must-bring to protect yourself from mosquito bites which are even a greater threat during the wet seasons.


So, which specifically, is the best season Koh Samui is known to travelers for? We’d say there’s no clear consensus on that. As you’ve seen, all the seasons have their pros and cons. While many tourists prefer the dry or hot seasons when things are bustling and there’s little rainfall, others prefer the wet and monsoon seasons when the environment is greener, and the atmosphere, calmer. Which would you prefer? It’s up to you!

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