Ideal Holiday 27°C to 30°C – day, 15°C to 20°C – night
Very occasional thunderstorm, winds in December early morning and evening, likely need blankets/jumper at night
30°C+ – day, 22°C – night. The odd thunderstorm
33°C+ – day, 20°C – night. Rain probable once a day, sunny spells
Koh Chang, Koh Kood, Koh Mak and Koh Wai have 3 seasons, the cool season which runs from November to February, the hot season from March to end of May and the rainy season from end of May to the end of October.
Thailand Climate – Cool Season
The best time to visit is during the cool season of November to end of February when the average temperature hovers between 27°C to 30°C, the mid to high eighties Fahrenheit and it is around 20°C in the evenings. December drops down to nearer 15°C to 18°C at night, chillier than you might think and causing more than a few to sheepishly seek out an extra blanket. The north east winds can be quiet strong during mid November to early January, especially during the early morning and late afternoon. Most importantly, however, it is almost guaranteed sunshine throughout, glorious blue, cloudless skies, light breezes and with just the odd thunderstorm or wet few days. The sea is calm with good visibility for diving and snorkeling.
Thailand Climate – Hot Season
The hot season covers the three months of March, April and May and the thermometer steadily climbs above 30°C, making the days very hot indeed and the nights not much different. An odd thunderstorm breaks the heat but it is a time for shade, fans and air conditioning, as the humidity will make things feel even warmer. The islands are still busy as the tourist season is just about bubbling away and April and May are peak holiday months for the Thais themselves. April 13-15th sees the Thai New Year Celebration of Songkran, complete with its water throwing festivities, a perfect way to cool off and May has the public holidays of Labour Day and Coronation Day, both taken as long weekends. The seas are still calm and the skies cloudless, but only the absolute devotees are able to take more than a few minutes sunbathing on the beach.
Thailand Climate – Rainy Season
The rainy season arrives towards the end of May, usually with quite severe weather and unrelenting downpours at the start, before settling into a rhythm of the heavens opening once a day, more often than not, at night. The temperature is in the high twenties Centigrade and the days seem much the same as other times of the year, with lots of sunshine and blue skies. The seas, however, have a different quality, with swells and white capping alongside highly dangerous riptides. Dive boats and snorkeling trips do still go out but the visibility is often much reduced and the water choppy. Speedboats tend to stay in harbour.
The problem for visitors seeking a beach holiday at this time of the year is that none of the sunny weather is guaranteed and a week’s stay might coincide with a time when the rains have set in, giving grey dull skies and lots of sitting in the bungalows waiting for it to stop. That said, the prices are as low as half, the island is much quieter, the waterfalls are in full flow and the forest in all its lush virescence, is teeming with life. You may also witness some magnificent tropical storms rolling in off the horizon, with the wind steadily picking up, the skies darkening and the claps of thunder absolutely deafening. Though not set in stone, the rain does get heavier again towards the end of the rainy season, September and October, with it now coming down off the mountains, a sign to the locals that the dry months are around the corner.
The cool season is often referred to as the high season (high, as in tourism) and the rainy season as the low season (low, as in tourism) or the green season (avoiding the word rain, for obvious reasons).