You can wonder which month is the best time to visit the island of Koh Samui but Koh Samui has much to offer no matter when you arrive on the island and each month also brings a change in the weather.
January in Koh Samui is top peak season, as the weather is at its most pleasant in the mid
20s Celsius. You’ll get plenty of sun without feeling suffocated by the heat and also very little rain, making your chances of getting a really great suntan better than ever.
The Chinese New Year usually falls in late January, and the island goes all out with celebrations, with reds and golds adorning every little corner. The large Sino-Thai community in Koh Samui is large and very active and you’ll see lots of Chinese tourists coming over to celebrate on the island. This translates to hotels that are often fully booked, higher airfare, and group tour companies being busier (and charging more) than usual. If you want peace and quiet while on Koh Samui, skip the second half of the month and especially the week around the Chinese New Year celebrations.
February is Koh Samui’s driest and less humid month, perfect for spending time at the beach without having to worry about afternoon downpours or melting under the sun. The month is only slightly warmer than January and still prime tourist season. When the Chinese New Year falls in early February, you’ll run into big crowds, street parties, and lots of fireworks as well, but after the 15th of the month, the island quiets down considerably.
Very little rain and almost no clouds make March a good time to visit, before things get really hot in April. Keep in mind that March also means “spring break,” so you’ll find lots of young people, especially near the beach and the main tourist areas.
April is Koh Samui’s hottest month. Since it’s also one of the most humid months, not even the sea breeze feels enough, and air-conditioned places to escape to are a must. Songkran, the Thai New Year, falls in mid-April. Although it’s technically just one day, the celebrations last longer than that. The main festivities concentrate on Chaweng or Lamai Beach Road, and the temples around the island, and mainly consist of people attacking each other with spray guns innepic water battles. Being a foreigner is no excuse in fact, it will likely make you more of a target so come prepared to be constantly wet for at least a couple of days.
May is just as hot as April but a little more rainy, with about nine wet days in the month. That usually means short but intense downpours in the late afternoon a short relief before the humidity kicks up again. With the rains come mosquitoes, though, so evenings out are a little less comfortable.
Both June and July have average temperatures around 30 degrees Celsius (but can easily reach 35 degrees Celsius) and sea temperatures of around 28 degrees Celsius. This means jumping into the water won’t do much to help you cool down, and planning some indoor activities is just as important as your time on the beach. June is a great month for water sports, as moving will at least provide some relief because of the breeze.
While other Thai islands, including popular Phuket see a lot of rain in July, Koh Samui remains mostly dry, except for the rare but intense tropical storm. This, coupled with temperatures that remain in the 30s Celsius most of the time, means that you’ll see more tourists on the island simply because the choices for tropical destinations are fewer in July for tourists escaping the rain.
August sees some rain (about 10 days out of the month) but not enough to keep visitors away, especially since it’s still very hot and the rains tend to be very short. This is also the last very busy month until the high season starts in December, as people are still out on their summer break and heading to the beach.
Since kids go back to school in September, you’ll see the crowds thin out, and the beaches become quieter this month. Arrive at your favorite beach early in the morning, and chances are you’ll have the place all to yourself. This is the best time to travel if you want peace and quiet, and you don’t mind some rain here and there (there are more sunny days than rainy ones, though, so don’t worry).
October is technically part of the rainy season in Koh Samui, but the rough weather doesn’t arrive till the second half of the month-and even then, it’s just in the form of short afternoon rains, not all-day wet affairs. October tends to be cloudy, though, which can be good or bad depending on how much sun you’re yearning to see and don’t worry, you’ll still get a tan on cloudy days, as Koh Samui’s tropical location means strong sunshine all year long.
November is Koh Samui’s wettest month, with dramatic monsoon rains hitting the island about 15 days out of the month. Temperatures remain high at an average of 27 degrees Celsius, and so does the humidity index at 85 percent. Loi Krathong (also known as “the festival of lights”) falls in November, and it involves the practice of releasing little boats made of banana leaves and holding a candle into rivers or the ocean. Thousands of flames flickering over the water is a sight to behold and one of the highlights of November.
Your chances for sunshine are better in December, with an average of just nine days of rain compared to half a month in November. Humidity stays high at 85 percent, though, and will continue at that level until the dry season arrives in March. December is one of the “coolest” months of the year, with an average temperature of 27 degrees Celsius. By the second half of the month, the cloud cover is starting to open up, and the island sees more sunshine.