When visiting Bali it is important to take the weather conditions into account. Even though the Bali weather is understood to be sunny skies and cool breezes this is only half the story. The weather in Bali isn't split into 4 seasons but rather into 2. There's the dry season and the wet season, with the temperature remaining pretty constant across the year. The averages temperature in Bali is 28C all year and even in winter you can expect it to drop to only 24C.
The hottest time to visit Bali is during the dry season which lasts from April to Sep, with June to Sep being the peak season. There's very little rain at all thru these months and you should expect to have 99% of the time you spend in Bali with bright blue skies. There's slight rainfall during this time, but it is generally in the afternoon, and though if could be a heavy downpour, only last a short while and then the sun comes out again.
The other, less popular season to visit Bali is in the wet season, typically from October to March, because of the very wet conditions. During this time of the year you should expect awfully heavy rain for days if not for weeks at a time. It is this season that give Bali its dense tropical rainforests that it is known for. The high rain volume during the wet season gives the trees and plants lots of moisture to grow at a fantastic rate.
During the whole year you should expect to have a high humidity which is at its peak in the rainy months and can reach as high as 90% which if you are not used to it can be very stifling. When coming to Bali and you aren't used to living in a humid climate it is critical that you book a hotel that has air-con in order for you to acclimatize. The humidity is felt more inland where the coast gives way to a higher altitude and some areas are so dense with vegetation that some people can find it difficult to breathe.
The winds that blow in Bali are light to moderate and you don't get the serious monsoons and gales that are associated with many Indonesian s. There are some amazing storms that are grand to experience, but except for landslides there is no danger if you visit Bali during this time. Many folks still come to Bali in this time as you'll find the Bali accommodation is less crowded and you'll be capable of finding much better rates.
With Bali being such a little island that is known for its marine life and wonderful scuba diving areas it doesn't really matter when you come to go to if you are curious about diving. Even during the heavy rainy season you're still assured of some bright days, it is just that when it rains it really rains and you'll have to remain in the hotel in the heaviest of the downpours or spend some time doing some Bali shopping.
