Indonesia has a tropical climate with two seasons; dry and monsoon. The best time to travel is from April to October as this is the dry season. The monsoon season is from November to March, and for certain islands such as Bali, it is fine to travel during these months. The rain is generally limited to a couple of hours in the afternoon. In terms of temperature, there’s little difference between the winter and summer on most of the islands, with temperatures averaging 25C-30C all year round.
Sumatra and Java
The best time to travel to Sumatra and Java is from May to September. The monsoon season lasts from November until March, with most of the rain falling in the late afternoon. It is best to avoid travelling to Sumatra during these months as the monsoon rains can be very heavy, making roads inaccessible. Temperatures average 22-29 degrees all year round.
The dry season on Bali lasts from April until September, with May, June and July being the coolest months when temperatures ‘drop’ to 28C. The monsoon season starts in October and lasts until March, but in between the monsoon showers you can expect clear blue skies and plenty of sunshine. The hottest months of the year are February and March, with temperatures around 30C. The best time to go on a Bali adventure tour is in the drier, cooler months from May until August, with high temperatures during the day and cooler evenings.
Nusa Tenggara (Lombok, Flores, the Gilis)
The difference between the dry and wet season is bigger here than in other areas of Indonesia. The driest months are August and September, the wettest are November and February. The duration of the dry and wet seasons varies per island. The climate on Lombok is similar to Bali, and the same goes for Sumbawa and Flores. Generally, the closer to Australia you get, the longer the dry season.
Due to its irregular shape and the fact that it’s on a geographical borderline, Sulawesi has two very different climates. The South-West has its monsoon season from October to March. In the North, around Manado, most of the rain falls between June and July, but the dry season lasts from August until October. Temperatures can vary significantly; along the coast it can be very hot with temperatures of around 34C, whereas the hills can be cool with a maximum around 24C, cool enough to need a jumper in the evening.