Upon arrival and disembarking from the plane, one immediately notices the sudden rush of warm, wet air. Indonesia is a warm place. It has no spring, summer, fall, or winter, just two seasons: rainy and dry, both of which are relative (it still rains during the dry season, it just rains less). While there is significant regional variation, in most of the country (including Java and Bali) the dry season is April to October, while the wet reason is November to March. In highland cities such as Bandung in Java, the temperature is cool and pleasant, and many people from outside these cities are wearing jackets.

Indonesia's climate is definitely tropical. There is no Autumn or Winter and distinctive "dry" and "wet" seasons share the year. The East Monsoon, from June to September, brings dry weather while the West Monsoon, from December to March is moistureladen, bringing rain.

The transitional period between these two seasons is interspersed by the occasional heavy rain shower, but even in the midst of the West Monsson season, temperatures range from 21 degrees (70_F) to 33 degrees celcious 190_F except at higher altitudes which can be much cooler.
Heaviest rainfalls are usually recorded in December and January and humidity is generally between 75% and 100%.