Indonesia rainy season — month-by-month guide for Bali, Java, Sumatra and beyond
When does the rainy season start in Indonesia? A detailed breakdown by island with rainfall data, flooding risk and travel tips.
Overview
Indonesia straddles the equator and has one of the most varied rainfall patterns in Southeast Asia. The rainy season in most of southern Indonesia (Bali, Java, Lombok) runs from November to March, while the dry season is April to October. However, equatorial Sumatra and Kalimantan receive rain year-round with no true dry season. Understanding which island you are visiting and its specific rainfall pattern is essential for trip planning.
Bali
Bali's rainy season runs from November to March, with January typically the wettest month (350+ mm). Rain usually falls in heavy afternoon bursts rather than all-day drizzle. The south coast (Kuta, Seminyak, Nusa Dua) is drier than the central highlands (Ubud). Even during the wet season, mornings are usually sunny — plan outdoor activities before noon.
Java
Java follows the same November-March wet season as Bali. Jakarta is particularly flood-prone during January and February when heavy rain overwhelms drainage. Yogyakarta and East Java are slightly drier. The wet season is also the best time to see Java's waterfalls at their most impressive.
Sumatra
Western Sumatra (Padang, Bukittinggi, Lake Toba) is wet year-round, receiving over 4,000 mm annually. There is no distinct dry season — rain falls in every month. Eastern Sumatra is slightly drier but still humid. October to March is the northeast monsoon period with slightly heavier rainfall on the east coast.
Kalimantan (Borneo)
Indonesian Borneo has an equatorial rainforest climate with rain year-round. The wettest months are December to February. Orangutan watching at Tanjung Puting is possible year-round but river access is better during the wet season when water levels are higher.
Nusa Tenggara (Lombok, Flores, Komodo)
Eastern Indonesia is significantly drier than the west. Lombok, Flores and Komodo have a pronounced dry season from May to October with very little rain. The wet season (November to March) brings the monsoon. Komodo diving is best June to September when visibility peaks and manta rays are most active.
Frequently Asked Questions
When does rainy season start in Bali? ▾
Typically mid-November, with the heaviest rain in January and February. The season ends in late March.
Is it worth visiting Indonesia during rainy season? ▾
Yes — prices are 30-50% lower, tourist crowds thin out, and landscapes are lush green. Rain is usually 1-3 hours in the afternoon, leaving mornings clear. Avoid Jakarta in January if flooding concerns you.