Indonesia has a tropical climate with two seasons, dry and monsoon. The best time is from April to October, since this is the dry season. The monsoon lasts from November to March, and for some islands such as Bali, it is okay to travel during these months. Rain is generally a few hours in the afternoon. In terms of temperature, there is little difference between winter and summer on most islands, with temperatures averaging 25C-30C all year.
Sumatra and Java
The best time to travel to Sumatra and Java from May to September. The monsoon season lasts from November to March, with most rainfall in the afternoon. It is best to avoid traveling in Sumatra, in these months; the monsoon rains can be very difficult, when roads are inaccessible. Temperatures average 22-29 degrees year round.
Bali
The dry season in Bali is from April to September to May, June and July the coldest months when ‘drop’ temperatures to 28C. The monsoon season begins in October and lasts until March, but between the showers of the monsoon, you can expect a beautiful blue sky and sun. The hottest months of the year are February and March with temperatures around 30C. The best time to do an adventure tour of Bali is in the drier, colder months from May to August, the evenings with high temperatures during the day and cooler.
Nusa Tenggara (Lombok, Flores, Gili)
The difference between wet and dry season is higher than in other parts of Indonesia. The driest months are August and September is the wettest November and February. The duration of the dry season and rainfall varies according to the island. The climate is similar to Bali Lombok and Sumbawa and Flores same. In general, the closer you get to Australia, plus drying time.
Sulawesi
Because of its irregular shape and the fact that is it has a geographical boundary, Sulawesi two very different climatic zones. The Southwest’s monsoon is season from October to March. In the north around Manado, is the most rain falling between June and July, but the dry season lasts from August to October. Temperatures can vary considerably along the coast; it can be very hot with temperatures around 34C, while the hills can be cool with a maximum at 24 ° C cool enough to need a bridge in the evening.