Thailand, once known as Siam, is a tropical climate with a distinct wet season (summer) and an equally distinct dry season (winter). This is because Thailand, like most of Asia, is influenced by the Asian monsoon winds.

The wet season runs from May to October when the southwest monsoon is carrying moisture from the Indian Ocean. This period is generally cloudy, very warm and humid with frequent showers. There are two precipitation maxima in Bangkok. The first is in May at the onset of the wet monsoon. The second, even greater rainfall peak, is in September to early October when tropical disturbances are most prevalent.

The months from November to April are much drier as this is when the drier northeast monsoon winds blow. Rain is usually confined to a few days per month and falls mainly in the south, where the northeast winds can pick up moisture from the Gulf of Siam. Most days are sunny as well as dry, making the winter the best time of year for travelers to enjoy the sights of this beautiful land.

Typical of most tropical climates, there is little variation in temperature month-to-month, except in the north, where winters are cooler. March, April and May tend to be the warmest months because the sun is becoming more intense while the southwest monsoon, with it clouds and rain, has not yet developed.

BANGKOK, THAILAND