The best time to visit Thailand is when you want to come! I know you don`t want rainy days, so let me explain how the weather works here.
The weather in Thailand is divided in two: dry and rainy season. Rainy means monsoons. Thailand is a tropical, hot and humid country. The best time to visit Thailand is from November to March. The hottest month is April with an almost unbearable heat. I must to say during Songkran is amazing to get wet. Low season runs from July and August and shoulder season between April and June and September to October.
Thailand is a tropical, hot and humid country.
Mosoon is seasonal shift in wind direction according to the seasons of the year. It can cause heavy rainfall and in some countries, monsoon (rain) can cause real damage, but in others, such as Thailand, monsoons cause only constant overcast and torrential rain at certain times of the day. I came to Thailand in all months and it`s not that bad if you are in Bangkok, because everything still working and you can have a “normal” time.
BANGKOK is considered the hottest capital of Asia, with an annual average of 34ºC. In the rainy season, between April and October, the climate tends to be more pleasant, not exceeding 30ºC.
CHIANG MAI is more pleasant in high season. In the rainy season the weather is hotter. I just recommend you take care during the burning season (end February to middle March) if you have breathing problems.
ISLANDS have constant temperature throughout the year, with a very low variation that goes from 25ºC to 31ºC and the sea remains constant at 28ºC. Monsoon season ranges from afternoon showers to major flooding, rain is usually in short and boat services are limited in stormy weather. I went to Koh Samui during rainy season and most of days were sunny until 3pm.
Rainy season is different according to the region of the country.
From APRIL to OCTOBER it rains on the west coast, where are Bangkok, Chiang Mai, Phuket, Koh Phi Phi and Krabi.
From SEPTEMBER TO DECEMBER it rains on the east coast where are Koh Samui, Koh Tao and Surat Thani. Even in the sunny season, typical summer rainfall may occur.
The rain is strong and steady, usually in the early morning or late afternoon. Rain tends to be torrential and can cause flood on islands. Songkran festival is the beginning of the rainy season, in April. I remember my first time here and when November came, the rain just stopped and wind days made the weather in Thailand more pleasant. The good news is Thailand is not route of typhoon, unlike the Philippines and China, for example.
Before you choose your best time to visit Thailand, just keep in mind our world is changing. The global warming is mixing up everything and in last ten years precipitation is observed to be below normal levels and sometimes there is intense rainfall even during dry season.
Best time to visit Thailand