An Island destination trip is the perfect kind of vacation where you either do nothing all day or try everything you can. And Koh Samui is one of the hottest places for such a vacation. In 2019, almost 40 million tourists flocked to Thailand and its picturesque oceanside spots for enjoying days of lazing off in hammocks while the waves ebbed in the background, strolling along the white sand beaches, getting pampered by Thai massage, day-long islands journey by jet ski, a trip to the Night Market to indulge in local cuisines, or partying all night on beach club. However, in Koh Samui, the weather can be challenging. Before you book your trip, you need to know what Samui weather is like around the year.

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Koh Samui: Climate

Koh Samui generally has a sunny and pleasant climate, as expected of a tropical destination. Thailand lies between the Tropic of Cancer and the equator, making its climate uniquely warm and humid all year round. The humidity level stands between 70% and 85%, and the temperature averages around 28°C.

The climate in Samui is distinguished into three seasons; dry, hot, and rainy. The dry season runs from December to around February. For hotels and every tourist-related business, this is peak season. The temperature is warm with little rain and light wind and the sea is calmer. This kind of weather is the most bearable for international tourists.

Koh Samui: Weather Year Round

January – April 

Meanwhile February is the driest month of the year, with just 12% of the average train seen in November. March and April tend to be nice and dry unless your visit falls during Songkran.

March – May

Between March and May is the hottest time of the year. During these times, the temperature might reach 30°C+. You might experience heavier rainfall during this period as it marks the beginning of the monsoon. But if you can bear a higher temperature, this is the best time for beach and ocean activities.

June – August 

June and August are summer holidays in many countries, and it makes a mini-high season in Samui. As for the weather itself, it is a typical pattern of sunshine all day long followed by a thunderstorm in the late afternoon. 

September – December

The period of heaviest rainfall comes at the peak of the monsoon in September through November. It is not recommended to do scuba diving, island trips with boats, and other sea and beach-related activities during this time. The weather is the most unpredictable during this time and makes the visibility reduced by around 30%. The sea, as well as the winds, is rougher, too. It makes boat trips increasingly dangerous. But the upsides of the low season are lower hotel rates and less crowded beaches. 

Koh Samui: Best Times to Visit

There is no exact perfect time to visit Koh Samui, but depending on what kind of trip you desire, there are choices to consider.

Sunny Vacation

For travelers expecting the most sunny day of the year, the dry season during November to February, followed by the dry month of March through April might be the most ideal. The second choice is on June through August for the less-ideal sunny weather, but less crowded hotel and attraction

Hot Season Adventure

March and May is the hottest season of the year, and it might be hard to handle the temperature. But it is the best time for sea-related activities such as snorkeling, diving, kayaking, and taking boat trips to neighboring small islands.

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Koh Samui: Budget Travel

And if you are looking for lower hotel rates, and can bear the less-than perfect weather, you can consider traveling during September through November. However, during this time, you might want to stay away from any activities around the ocean and stick to indoor activities or spend time on the land to shop, eat, and blend in with the locals at Chaweng, or visit the Secret Buddha Garden.

After you get the idea of what the weather is like, there are a few things to consider in how you dress for your trip and what to bring:

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Koh Samui: What To Pack On Your Trip

What to Wear

With its humidity and warm temperature, as well as the modest culture of Thailand, aim for dressing light, but not too revealing.

Learn how to look clean and put together with simple attire. Article of clothing such as shirt, T-shirt, shorts, pants, and dress is preferable and linen or rayon fabrics are recommended. Such garments are perfect for tropical locations as they are light and water-absorbent. Bring a light jacket as well, in case it gets more chilly at night or when it rains.

Swimsuits are essential, as Koh Samui is a beach-oriented holiday destination. But it is not recommended to wander out of the beach and resorts with only your swimsuits. So make sure to bring cover-ups such as a beach tunic and shorts.

While in Koh Samui, or Thailand, lots of tourists want to make the most of their trips by visiting local sacred places such as temples and shrines. In these places, modest clothes are a must. Both men and women should wear clothing that falls below the knee and covers the shoulders as a minimum, so bring long pants, skirts, or dresses for such occasions, as well as closed-toe shoes.

Must-Have Items You Need to Pack for the Trip

Knowing the climate situation of Koh Samui, there are few essentials you would not want to forget in your trip:

1. Sun Gear

With the perpetually sunny weather, the sun can be scorching at times. So if you are on walking trips, a hat is highly recommended. A light-colored hat and light-colored outfits are the safest options for your outdoor activities on Thai streets.

Sunscreen and sunblock are essential for the climate. Choose the product with high SPF and apply and reapply for every occasion.

2. Mosquito Repellant

One of the often-forgotten aspects of high humidity areas is mosquitoes! Pack mosquito repellent in spray or ointment form to protect your skin while on a trip to the city or a nature walk, especially during the nightfall. You can also use gear such as a mosquito repellent bracelet. It is recommended too for you to prepare electric mosquito-repellent devices or mosquito nets in the hotel or resort room where you stay as well. 

3. Hair and Skin Care Needs

If you’re not from a tropical country, the change in the heat and humidity might have an unwanted effect on your hair and skin. Consider investing in a konjac sponge. For many travelers, it helps your skin breathe after sweating all day long and constant use of sunscreen. For your hair, you might want to consider anti-frizz hair products like shampoo or hair oil to combat the humidity frizz. Be mindful in buying hair products from locals too if you are not Asian, as Shampoo sold in local marts is specifically formulated for Asian hair.