There are 3 seasons in Thailand – the winter, the summer and the rainy season.
Winter – November to February brings a relative low humidity with daytime temperatures between 28 and 30 degrees C. This time of the year is climatically the best for many tourists, especially those who come from the winter countries in Europe and North America. Except for the Southern Gulf of Siam with Koh Tao, Koh Phangan and Koh Samui islands, this is a good time to enjoy swimming – see “beach weather” below.
Summer – March to May is the hottest time in most areas of Thailand.
Daytime temperatures go up to 38 degrees C in shadow, the humidity is still low but towards the end of the Thai summer it rises. During this hot period visibility conditions for photographing are not optimal. This applies above all to the northern regions and the Isaan – northeast of the country. In summer the paddy fields and plantations are underused because there is not enough water to grow rice. Whole areas appear as shades of brown and yellow.
Rainy season – from May to October prevails in many parts of the country a very high humidity. The sea is rough but the weather warm.
It is rare to have a several days of continuously rain – rainy season usually means several short heavy showers each day.
In our opinion, this period of the year is best make an overland tour to the north, northeast, east and central Thailand, because the colours are beautiful, the air is clear with good visibility before and after the rain.
In addition, in the rainy season, hotel prices are cheaper than in winter, and you will find far fewer tourists than in the other seasons.
How is the beach weather in Thailand?
Coastal areas with beaches and islands can be divided into 3 zones:
Northern Gulf of Siam
Koh Chang, Ko Kood, Koh Mak, Koh Samet, Chanthaburi, Pattaya, Rayong, Petchaburi, Chaam, Hua Hin, Pranburi
Southern Gulf of Siam
Bankrud, Bangsaphan, Chumpohn, Koh Tao, Koh Samui, Koh Phangan, Khanom, Sichol, Nakorn Si Thammarat, Hat Yai, Songkhla, Narathiwat, Yala.
Andaman Sea
Ranong, Koh Payam, Koh Kor Khao, Koh Pratong, Khao Lak, Similan Islands, Surin Islands, Phuket, Phi Island, Koh Racha, Krabi, Koh Jum, Koh Lanta, Koh Hai, Koh Kradan, Koh Mook, Koh Libong, Koh Sukorn, Koh Laoliang, Koh Bulon Leh, Koh Lipe, Trang, Satun.
Northern Gulf of Siam
Best bathing time: November to April.
Calm sea, barely any underwater currents, suitable for snorkeling and diving.
Transitional period: May – June and October
During this time you may be lucky and the weather is just as good, but it also be that you can’t swim in the sea for days, because of high seas and stormy weather.
Bad season: July to September
High temperatures with high humidity and very rough sea. Often the water comes far up the beach bringing a lot of waste from the sea. In many places, there are also underwater currents and it is not allowed to swim in the sea.
Southern Gulf of Siam
Best beach weather: February to September.
Low humidity, calm seas, hardly any waves. Well suited for snorkeling and diving.
Transitional period: October and January
During this time you may be lucky and the weather is just as good, but it also is that you cannot swim in the sea for days, because of high seas and stormy weather.
Bad season: November-December
In the southern Gulf of Siam it rains generally less than other regions of Thailand, however November and December often experience strong winds and turbulent sea. Diving and snorkeling is often not possible. It may even be that because of rough seas large ships stop operating between the islands of Koh Samui, Koh Phangan and Koh Tao. Similarly affected are the flights to and from Koh Samui.
Andaman Sea
Best bathing time: November to April
Calm sea, barely any underwater currents, suitable for snorkelling and diving.
Transitional period: May – June and October
During this time you may be lucky and the weather is just as good, but it also be that you can’t swim in the sea for days, because of high seas and stormy weather. Several ferry and speedboat companies shut down their operations from May to October between certain islands.
Bad season: July to September
High temperatures with high humidity and very rough seas. Often the water comes far up the beach bringing a lot of waste from the sea. In many places, due to underwater currents it is not allowed to swim in the sea. Several ferry and speedboat companies shut down their operations from May to October between certain islands.