The climatic conditions of the Thai Peninsula
Often, people have no exact knowledge about the climatic situation in Thailand, especially about the conditions of South Thailand, which bear their specific character. Therefore we like to give a short overview about the climate in Thailand in general and the Peninsula specifically.
In the continental part of the country there are four seasons, which are more or less strongly marked. These seasons are mainly due to global equatorial winds, the monsoons. The term "monsoon"is Arabic and means nothing else than "season". During about four months, from mid of June till mid of September or beginning of October, the southwest monsoon is prevalent and showers the whole country with heavy rainfalls. Then, a so called inter mon-soon period starts. The southwest monsoon stops slowly and the climate is getting dryer, the temperature still moderate, and during November and December (especially the nights) may be even cool. Then in December the monsoon changes its direction diametrically. Now it blows from northeast to south west and brings the country dry weather with very high temperatures and a minimum of humidity. At the end of March, the northeast monsoon stops and another inter monsoon period starts, warmer now and slowly getting wetter, than the last inter monsoon period. About mid of April (when Thai people celebrate their Songkhran) the first rainfalls start, often in form of heavy thunderstorms, which usually do not last long. Often this first inter monsoon period is misinterpreted, as people say "The monsoon starts early this year. " In fact this is not yet the southwest monsoon, which actually only starts again about mid of June. From March till July large low pressure-areas, cyclones and typhoons arise from the Indian Ocean and usually bring additional heavy thunderstorms and rainfalls to the Southeast Asian countries, also to Thailand. These may locally last for days and even weeks and are the main cause for the above mentioned misinterpretation.
Thus the year in Thailand may be divided as follows:
- December - March : Dry Season = Winter- or Northeast monsoon
- April - June : 1. Intermonsoon period
- June - September : Wet Season = Summer- or Southwest monsoon
- October/November : 2. Antimonsoon period = "monsoon retreat”
The climatic conditions of the Thai Peninsula, especially those of the regions south of the Isthmus of Kra, are already very similar to those of the inner tropics. A fact, which is caused by the specific geographical situation of this part of the country: A comparatively narrow land mass is bordered by the endless waters of the Indian Ocean. High degrees of humidity combined with fairly high degrees of temperature are responsible for the climate throughout the year. Generally we also find the four seasons as described already, but the influence of the Indian Ocean and especially of the low pressure areas with their typhoons and cyclones is prevalent.
The southwest monsoon, coming from the Andaman Sea, showers the west coast of the Peninsula and also casts its rains mainly over the mountainous backbone of the peninsula, bringing only few rainfalls or any rain at all to the east coast or such islands as Ko Samui and Ko Phangan. But the monsoon rains mostly last for one up to a few hours per day, sometimes even interrupted by beautiful sunshine and good weather for several days. Sometimes however, very heavy long lasting rainy periods of several days or even a week or more are determinant not only for the weather on the west coast, but also for that of the east coast and the islands off the east coast. These periods of "bad weather" are not caused by the monsoon, but they are due to the cyclones, which not even spare islands like Ko Samui or Ko Phangan. But generally, the east coast and the islands off the east coast have dry sunny weather during the southwest monsoon period, but get rain and cooler weather during the winter- or northeast monsoon period. During this time, from December until May or even beginning of June, usually the weather on the west coast is fine and the Andaman Sea invites for swimming, snorkeling and diving.
More information and a weatherforecast: