Updated June 18, 2025

By now you may be familiar with the allure of Koh Samui as one of Thailand’s premier vacation destinations. The island has come a long way from being a backpacker’s paradise, offering not just luxury accommodations but also a wide range of tourist-friendly activities and attractions for every visitor to enjoy.

Still, there are some things that even guests at the most lavish private villas on Koh Samui need to remember before arriving on the island. Knowing these facts about the island can not only save these guests discomfort, but may also spell the difference between a good trip and an extraordinary one.

Related article: How to Travel Sustainably in the Island Paradise of Koh Samui

10 Must-Know Facts About Koh Samui for Travelers

These facts about Koh Samui act as “must-know” tips for travelers who might not know what to expect on their visit to the island. It’s important to keep in mind that Koh Samui is still very much an island, and has yet to experience the development that places like Bangkok and Phuket have gone through as tourist destinations.

1. The Weather is Humid

Photo: The swimming pool area at Villa Raku can help you beat the heat.  

While the average temperature around Koh Samui at any given day is around 30 degrees Celsius, the humidity and high heat index makes it feel warmer than it really is. It might be a little uncomfortable at first, but with proper hydration and warm-weather outfits, you will hardly feel annoyed by the humidity.

2. Rain Can Happen at Any Time

As a tropical island, Koh Samui embraces the sunshine as much as the rainy days. The heaviest rains happen during the rainy season, which falls in September to November. Despite the rain and occasional storm, the island is still a year-round destination, and Koh Samui’s skies still have plenty of sunshine even when the weather isn’t as hot.

Related article: Fun Activities to Do in Koh Samui When It Rains

3. Not Every Local Speaks English

While some locals can speak basic English to communicate with customers and guests, it’s also recommended to start practicing your basic Thai phrases and greetings for better interactions. You can even ask the in-villa staff members to help you brush up on your Thai language skills to help you learn more about Thai etiquette and culture.

4. Tap Water is Not Drinkable

If you’re wondering why your villa gives you complimentary bottled water, the explanation is quite simple: the tap water in Koh Samui is not safe for drinking. For those of you who need to stay hydrated, bottled water is widely available at supermarkets, convenience stores, and even restaurants around the island.

5. Public Transportation Comes with Risks

You will find several choices of transportation on Koh Samui, such as tuktuks, motorcycle riders, and songthaews, but the island doesn’t have its own official form of reliable public transportation. Thus, it is recommended that you make arrangements in advance for a car and driver to take you around the island. This ensures that you will arrive safely at your destination.

6. Thais Drive on The Left

Another reason why booking a car and driver in advance is recommended for your trip to Koh Samui is due to the fact that Thailand’s motorists drive on the left, which means that the steering wheel is on the right-hand side of the car. This can be a safety risk for tourists who are not used to driving left, especially when they’re not used to dealing with local motorists.

7. You Can Use a Thai SIM Card for Mobile Access

These days, mobile access is a must for every traveller. Assuming that you have an open-line mobile phone that is not tied down to your home country’s provider, you can easily purchase a SIM card to access mobile calling and data services in Thailand from any convenience store in Koh Samui. Just make sure that the card fits your phone, and don’t forget to top up whenever you can.

8. Bring Your Own Baht

In Koh Samui, the Thai baht is the official currency, just like any other provinces in Thailand. You can find banks and currency exchange counters on the island, but just to be sure, try to bring your own baht before arriving in Koh Samui, since not all villas are within walking distance of the nearest exchange counters.

9. Keep Voltage In Mind for Electrical Devices

While many villas now offer international plug sockets, it’s still worth remembering that electrical outlets in Thailand can go pretty high on voltage. Any device that runs on a lower voltage, especially hairdryers that run on 110-120 volts, will be damaged when plugged into a 22o-volt outlet. It’s best to leave the low-voltage gadgets at home, and ask for an adaptor when necessary.

10. Expect Mosquitoes

Insects and warm weather are like best friends, and mosquitoes are among the top insects you will come across in tropical islands like Koh Samui. If you’re going to explore outdoor or rainforest attractions such as the Secret Buddha Garden, mosquito repellent is a must, and many brands of insect repellent are available from stores on the island.

Related article: Travel Calmly, Explore Freely: Why Koh Samui Is A Safe Choice for Tourists

Learn The Facts Before You Go to Koh Samui

Being informed is the first step toward making your trip to Koh Samui a safe and rewarding one. Knowing the important facts for travelers can guarantee more than just a good time–it can save a lot of time and money that can go toward the most enjoyable parts of the trip.

The most important part of every trip is the memories that you and your loved ones can make during your stay on Koh Samui. If you have any questions about the island, feel free to ask your villa’s Guest Experience Services staff prior to your arrival. They can give tips and guide you toward activities that can make the biggest difference to your Koh Samui stay.

Start your trip-related research with our Koh Samui Travel Guide.

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Featured image credit: travels.kilroy.net