Thailand is big and at the same time the weather may vary a lot in different regions of the country.
Weather in Central & Northern Thailand
In the northern and central parts of Thailand the seasons are clearly defined. Between November and May the weather is mostly dry with little rain expected throughout the region for much of this time. The dry season here is broken up into the periods of cool season (November to February), when it can get quite chilly in the north and northeast, and hot season (March to May), when it is not unusual for the temperature to reach even 40°C.
The wet season in the northern and central parts of Thailand is from May to November. The region is dominated by the southwest monsoon, during which time rainfall is at its heaviest. The rain usually comes in the form of short showers, lasting an hour or two. As the rainy season progresses, the rain can become heavier and more constant, traditionally reaching peak levels in August and September.
Different weather conditions in the northern and central Thailand destinations are notable in our weather ratings chart.
Weather in Southern Thailand
The south of Thailand has only two seasons - the wet and the dry. These seasons do not run at the same time on both coasts of Southern Thailand. On the west coast the southwest monsoon brings rain and often heavy storms from April through to October, while on the east coast the most rain falls between September and December.
Weather on the West Coast (Andaman Sea)
From November to March, many consider conditions to be at their best on the west coast. A cooling wind keeps the heat at bay and makes the daytime more comfortable in places such as Phuket, Krabi, Koh Phi Phi, Khao Lak and Ko Lanta. Thanks to the breeze, the humidity levels are lower than later in the year.
From March to May the temperature rises as the cooling wind departs and the humidity rises. In April monsoonal weather usually arrives, which is expected to last until October. Peak rainfall levels are usually experienced in September and October. Outside of these months, the rain can often come in a short, heavy shower, usually in the afternoon.
All West coast destinations have similar weather conditions throughout the year as they all experience the impact of the Andaman sea. Temperatures and weather conditions in these locations might differ a bit in short term but in long term it's not notable.
Weather on the East Coast (Gulf of Thailand)
From January to March you can expect good weather on the east coast, with little if any rain, and refreshing winds helping to keep temperatures more moderate in places such as Koh Samui, Koh Phangan, Koh Tao. From March, temperature starts to rise, usually reaching peak levels in April and May.
In May and June a little rain is expected, usually in the form of an hour-long afternoon shower, clearing the way for more blue skies and bright sunshine. In September the monsoon is expected, bringing plenty of rainfall and a rise in humidity. Rainfall usually peaks between October and November.
Some parts of the Gulf of Thailand experience different weather.
Koh Chang and other islands on the eastern side of the Gulf of Thailand experience similar weather patterns to the beaches along the Andaman Sea coast with wet season occurring between May and October.
Different weather conditions on the East Coast destinations are notable in our weather ratings chart.
Few regions of Thailand are included in your trip plan? You can find out when is the best time to complete your own Thailand trip itinerary.