Bali has 2 seasons, the wet season and dry season. There is no 4 seasons like you might expect in other geographical locations. The main difference between the 2 seasons is there is more rain hence the name but generally that's the only change in climate conditions.
The temperature itself tends to remain relatively consistent in both the both seasons regardless of the rain. However the rain does temporarily cool things down. For some the rain can be a welcomed change to the frequent sunny days during the dry season.
The average temperature range during the wet season is approximately 29° C - to 32° C (82.2° F - 89.4° F). The humidity can become higher during this season due to the cloud cover and rainy conditions making it feel warmer than it really is.
It's between the months of November and April. It tends to peak during the middle of this period and at times rain can be quite heavy for a few hours a day or more.
During this season it can be at times particularly warmer and more humid than the dry season due to the heavy rainfalls. Bali has many forests and lush green nature. This is as a result of the tropical humid weather combined with the rain.
It's difficult to say 'exactly' how much it rains during this season because it does vary and can be unpredictable at times. Generally though it tends to rain in the afternoons during the wet season for about an hour or so. Usually it's a very heavy shower for that period of time then it slowly backs off to a light shower.
Many travellers and even the locals find these afternoon showers quite refreshing after a hot sunny day. Bali is hot all year around so you will always be wearing light summer clothing. You can still have just as enjoyable a holiday in both the wet and dry seasons.
When it's the wet season you can be sure to find cheaper holiday packages to Bali than that of those in the dry season. You can save quite a bit of money by deciding to take your Bali holiday during this season while still experiencing a wonderful Bali holiday.
Although it can become quite humid with the rains, after feeling the intense heat of the sun all day, the rain can actually be quite refreshing. You may even be tempted to walk around in the rain to cool off. The rain can certainly take the sting out of the hot sunny days in Bali.
I know what the climate is like in Bali in both the wet and dry seasons. I have found that it actually seems to be warmer during this season that in the dry season. This is probably due to the higher level of humidity compared with the dry season.
In the dry season is still great warm weather but it does tend to get colder at nights and some afternoons aren't quite as warm. You can still go swimming everyday and everything but it's just not quite as warm during the dry season from my experience.
All in all you can still have a great holiday in Bali in any season. The wet and dry seasons are typical of any tropical country that is within close proximity to the equator.