There are three distinct weather seasons on the tropical island of Koh Samui: the dry season (December until February), the hot season (March until August) and the rainy season (September until November).
Tropical weather is notoriously unpredictable. When it’s good, it’s good. And when it’s bad, it’s very bad – torrential downpours, monsoon winds and floods that turn roads into rivers are commonplace in many South East Asian towns. Thankfully the average flood on Samui only reaches a few inches and is more of a photographic opportunity than a reason for panic. Resilient locals trudge through the murky water on foot, whilst others bravely chug through the roads-come-rivers on motorbikes, seemingly unconcerned with the potential consequences of water running into their vehicle’s engine.
But there’s a reason people flock to Ko Samui every year in the thousands. Well, many reasons actually. Not least because of its abundance of sun, sea and sand – the perfect holiday combination. Surrounded by sea, dotted with beaches, and getting an average of about 6 hours of sun a day, sun, sea and sand is certainly what you’ll get. The island provides the perfect environment for sunbathing, relaxing in the pool or doing water sports. The Samui weather ensures that there are plenty of water sports that you can enjoy during your stay too, from windsurfing to jet skiing, and all are accessible from Chaweng Beach.
Warm seawater temperature is another great draw to the island. Samui’s sea stays pretty constant throughout the year at a very comfortable 29 degrees Celsius. Air temperatures average at about 28 degrees Celsius and although it gets a few degrees hotter in the summer and a few colder in the winter, there’s not a great deal of change throughout the year.
Whilst the ‘best’ time to visit Samui is generally known to be during the dry season (from mid-December through till April) it’s actually an all-year-round holiday spot. From halfway through September until the middle of December is the ‘rainy’ season, but as many travellers who disregard this warning find, it only rains for a short but heavy burst at about 3:00 pm before returning to being dry again. After this usually only hour-long downpour the air loses that thick humidity that’s associated with tropical countries and becomes fresher, which is why many see it as a plus-point.
Koh Samui seasons: dry season, hot season and the rainy season
Koh Samui’s seasons are broken down into three main categories: the dry season, the hot season and the rainy season. The dry goes from December to February, when the temperature will be a little but cooler so you don’t get that sweltering midday heat but it’s still wonderfully warm. It’s the most popular of the seasons and therefore busiest time of the year on Samui.
But if it is that sweltering heat that you’re after, then perhaps the hot season’s the time for you to go. During this period you’ll get that 30+-degree heat and a lot of fairly strong sunshine, with not so many clouds – so remember to wear sunscreen! The wettest time of the year is from September until November, but as mentioned earlier the rain tends only to fall for a small portion of the day, leaving the rest dry and sunny – albeit a little cloudier than other times of the year.
Many people head out to Koh Samui deliberately during the rainy season because it’s at this time of year that you get great deals on flights and hotels. On many hotel websites there will be a clear distinction between peak and off-peak prices – peak sometimes being almost 50% more. But the island’s also much less busy during the off-peak season, so those who prefer a quieter holiday come for that reason. There are fewer people in the streets, shops, restaurants, bars and nightclubs. But not too few, because lots of other people have got the same idea too!
Whatever season you come to the island during there are a few items that you mustn’t forget. A hat is the first one, but if you didn’t remember to pack one, or decided not to do so because it’s too big to put into your suitcase, then you’ll easily be able to pick one up while you’re here. There are countless stalls up and down Chaweng Beach Road where you can buy one for a bargain. Caps with logos from all over the world are available and there are those brandished with varying sports teams as well as ‘designer’ ones. Summer hats with wide brims are popular with ladies and trilbies with men. And of course you can barter down the price of all of them.
Sunscreen is another staple item while on a holiday island. If you didn’t bring your own then you can easily buy some at one of the many pharmacies that you find on Samui. Just walking up and down Chaweng Beach Road you’ll pass a pharmacy every few minutes. One particularly good one with a wide selection of goods and great prices is the chain, Morya Pharmacy, of which there are numerous outlets on the island. They’ve even been known to throw in a free gift or two for good customers.
We all know what to do when it's sunny: go to the beach, have a swim in the pool or laze around on a deck chair.
But what about when it's overcast? Many people feel stumped looking up at the gloomy sky and then down to the beach, which somehow looks a little bit greyer. Days like this are great for outdoor activities like trekking up a waterfall because as the sun's not out it's not too hot and you're less likely to get burnt. Namuang Waterfall 2, is a great day out for all the family. It's a beautiful natural waterfall that you can climb up and swim in. And if you go the waterfall don’t forget to check out the famous safari located at the foot of the hike where you can ride elephants as well as see tigers and many other animals. Because whatever the Samui weather, there’s always something fun to do on Koh Samui.