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 north and north-east are generally cooler than Bangkok in winter and hotter in summer.

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. 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.
 

Average Daytime Temperature ( ºC) - Central Thailand

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
30	31	34	36	35	33	32	33	32	32	31	30

Average Rainfall (cm) - Central Thailand

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
1.0	2.5	3.5	6.0	8.0	14.5	16.5	17.5	30.0	21.0	7.0	0.5