There are five tourist seasons known in Bali, you should pick the best one that suits you depends on your own considerations and variables such as time, money, weather conditions, and the accessibility.
The Pre-prime Season ( April-May). Hotel rooms in Bali are readily available, while the rates, the crowds and the weather are moderate
The Prime Season ( May-September ). It is usually a sunny and dry period in Bali. During this season, the school holidays that occur in Indonesia makes the domestic tourists flood the island with crowds as well as the international tourists. The month of August is usually full of offers for tourists / visitors such as promotional hotel rates and interesting tour packages, while the restaurants offer special menus with interesting pricings in conjunction with the celebration of the Indonesian Independence Day. Foreign and domestic tourists / visitors can join in on the various folk celebrations of Indonesian independence held in Bali. It is best for you to book your hotel room at least a month prior.
The Post-prime Season ( September-mid December ). Hotel rooms in Bali are readily available again as schools in Indonesia begin their new curriculums, therefore not many domestic tourists can be seen during this season.
The Holiday Season ( mid. December-early January ). Domestic and international visitors flood the island for Christmas and the New Years eve. Just like the prime season, many promotions and attractive prices are on offer by the hotels as well as the travel agents and the restaurants. However, it is the time when the dry season changes into the wet season.
The Wet Season ( January-April ). Just like the rain, everything else such as prices, crowds, as well as room bookings seems to come down. It is trully a refreshing period after the dry season, and many sightseeing and adventure features on the island, such as the agrarian life, majestic temples and also the royal water palaces and gardens in the central regions, are best to be enjoyed during this season. However, the tropical rainy season will always leave plenty of sun for the coastal lovers.