Thailand’s climate is tropical, high both in temperature and humidity, and dominated by monsoons. April and May are the hottest months of the year, when even the locals are moved to complain about the heat. June sees the beginning of the South West Monsoon, and brings with it the rainy season, which continues intermittently until the end of October.
From November to the end of February the climate is much less trying with a cooling North East breeze and a reduction in the humidity level. This is also the main tourist season, and the best time to visit Thailand.
The area of Thailand north of Bangkok has a climate determined by three seasons whilst the southern peninsular region of Thailand has only two.In northern Thailand the seasons are clearly defined.
Between November and May the weather is mostly dry, however this is broken up into the periods November to February and March to May. The later of these two periods has the higher relative temperatures as although the northeast monsoon does not directly effect the northern area of Thailand, it does cause cooling breezes from November to February.The other northern season is from May to November and is dominated by the southwest monsoon, during which time rainfall in the north is at its heaviest.The southern region of Thailand really has only two seasons — the wet and the dry. These seasons do not run at the same time on both the east and west side of the peninsular.
On the west coast (Phuket) the southwest monsoon brings rain and often heavy storms from April through toOctober, whilst on the east coast (Koh Samui) the most rain falls between September and December.Overall the southern parts of Thailand get by far the most rain with around 2,400 millimetres every year, compared with the central and northern regions of Thailand, both of which get around 1,400 millimetres.
Average Daytime Temperature (oC) – Central Thailand
Jan Feb MarAprMayJunJulAugSepOctNovDec
30 31 34363533323332323130
Average Rainfall (cm) – Central Thailand
What clothes to Wear in Thailand?
For the Western visitor there is no such thing as “cool”. Just cooler than “hot” and “drier than humid”, so light cotton clothing is the order of the day, but around Christmas and New Year it’s good to have a light pullover when you go out in the evening for it’s sometime really cool (under 20 C). Don’t worry about bringing too much clothing with you, as almost everything can be purchased locally, at a fraction of the price you will pay at home. Do remember that the tropical sun can be quite fierce so a hat is useful, and don’t forget to use a good sun screen.