Weather in Koh Samui - tourist season
At any time of the year visitors will be satisfied with the weather in Samui and the coastal area. During the high season, from December to February, the weather temperatures on Samui hover at around 30 degrees centigrade. Short tropical downpours can still occur, mostly in December, but this is still considered the best season for Europeans to visit as the weather in Samui is cooler than later in the year. The seas at this time of the year are calm and generally clear, and the breezes are light. See a month by month review of Samui weather.
From March to June the weather can get very hot indeed on Samui, up to 40C/100F. There is little or no rain during these months, which can cause water shortages, and the pace of life slows right down to compensate for the heat. The sea remains calm and low tides can lead to very shallow waters on the island’s beaches. The wind picks up again in May, and this is a popular time for off-season visits. Late in the afternoon huge thunderstorms sometimes build offshore and come crashing into the island.
The weather on Samui during July to September is slightly cooler, with a mini monsoon season that brings occasional storms and periods of heavy rain. These are also popular months for visitors, who can still guarantee plenty of sunshine during their holiday.
October and November see more rain than other months, although even then it doesn't normally fall every day. Unlike many other parts of the country Koh Samui doesn’t have a prolonged or predictable rainy season. During the wettest periods there are rarely more for than two or three days without sun, even during November, which commonly considered to be the monsoon. However, the weather in Samui is quite difficult to predict during this time and the seas can be unusually rough.
No matter which season you decide to visit Koh Samui, as a westerner, one thing you will rarely feel is cold as Samui enjoys good tropical weather. Join our forum to learn more about life on Samui.
Koh Samui monthly weather guide
Weather in Samui in January
After the New Year has the hit, the island’s weather on Samui is quite temperamental. The northeast monsoon season has departed and it starts getting warmner, but still with a chance of rain. If it does decide to shower, it should only be a short burst. It is the most popular season and hotels can be full and premium priced.
Weather in Samui in February
Generally, this time year sees a dramatic reduction in the winds, and sports like wind surfing and kite surfing on the east of the island come to a standstill. Temperatures are getting into their mid-30s by day and there is not much let off at night. The weather in Samui remains dry in February however, thus it’s a popular time to visit, during the Northern winter.
Weather in Samui in March
Although weather is warm in Samui in March, this is an ideal time to take trips out to the neighbouring islands if boats are not your favourite mode of transport. The seas are generally quite tranquil and it makes ideal weather for scuba divers and snorkelling. The sun is reaching its daytime peaks and it can become unbearable in the midday heat.
Weather in Samui in April
April is traditionally the hottest month of the year in Samui weather -wise. The Sonkran water festival takes hold and it makes for the best way to cool down. If you see rain, you will be blessed as it does not happen often at this time. Expect temperatures in the forties (celcius) without the benefit of a seabreeze.
Weather in Samui in May
The season quietens down from May onwards on Samui, and the weather remains hot, while the rains are yet to arrive. You can get good discounts on hotel rooms at this time, and enjoy plenty of sunshine, but careful of sunburn!
Weather in Samui in June
From the middle of the year in June, the weather will start its long transition into the rainy season. The rainfall average will steady for the next four months and temperatures will decline; it doesn’t mean it gets cold, just cools off from the cloud cover, but becomes very sticky with humidity.
Weather in Samui in July
The start of the European school summer holidays brings unusual weather to Samui and the surrounding islands in July. Hotels and guesthouses start to get busier and the weather can be volatile with crashing waves on a rainy day to sunshine and still air the next, so it really can be hit and miss.
Weather in Samui in August
As the schools have finished, the influx of backpackers heading to the island rises quite well. Many head over for Koh Phangan and relax but there’s no real need to book in advance and prices are ‘low season’. Like in July, the daily weather can be quite random: hot and sunny one day, rainy and windy the next.
Weather in Samui in September
Heading out of the summer season in September can be the start of the infamous Samui rainy season. Temperatures do not fluctuate much throughout the year but on even slightly higher ground night-times can get cooler. It’s one of the quietest months on the island but can still be pleasant.
Weather in Samui in October
The rainy season has touched down officially so remember your raincoat or brolly because you are likely to need it. There is still time to sunbathe, but if you are there for two weeks do not plan on a deep tan.
Weather in Samui in November
This is possibly the only time of year you may want to avoid because of the weather. November can see many flash floods around the island and although the local council has worked on installing new flood defences, you may well see locals canoe down the street outside the bar you are stuck in.
Weather in Samui in December
December is bar far the most popular month to visit Samui, and the weather is agreeable, cooler, but with the chance of afternoon showers even if the rainy season has finished for the rest of the country. Expect crowds and high season hotel room prices.
