Is It Monsoon in Indonesia? Rainfall and Weather by City and Month

🇮🇩 Indonesia 10 CITIES
Plan around the monsoon

Is it monsoon in Indonesia?

Indonesia's islands don't all share one monsoon calendar. Bali, Lombok, and Flores, all in the Lesser Sunda chain, run almost identically: a rainy season from November through March driven by the northwest monsoon, and a dry season from June through September, with August historically the driest month across all three. Java, home to Jakarta, Bandung, and Surabaya, sees a longer rainy season, October or November through May, and a dry season, June through September, when none of the three are directly affected by tropical cyclones according to their own climate records. Bandung, sitting at elevation in the island's interior, runs noticeably cooler than the other two year-round.

Padang, on Sumatra's west coast, Balikpapan, on Kalimantan's east coast in Borneo, and Medan, on Sumatra's north coast, add a third pattern again: all three sit close enough to the equator that none has a real dry season at all, every month historically sees well over 100mm of rain, though each has its own comparatively calmer stretch within an otherwise wet year. Makassar, on Sulawesi, runs on a sharper pattern of its own: a genuine wet season from November to April, driven hard by its west-facing exposure to the northwest monsoon, and a genuinely dry one from June to September.

Regions at a glance
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Lesser Sunda Islands (Bali, Lombok & Flores)
These three islands share an almost identical climate: rainy from November through March, dry from June through September, with August historically the driest month across all three. All three can occasionally be brushed by tropical cyclones passing to the south, most often January to mid-April.
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Java (Jakarta, Bandung & Surabaya)
All three see a longer rainy season, October or November through May, and a dry season, June through September. None is directly affected by tropical cyclones. Bandung, at elevation in the island's interior, runs noticeably cooler than the other two year-round.
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Sumatra & Kalimantan (Padang, Balikpapan & Medan)
All three sit close enough to the equator that none has a real dry season. Padang sees comparatively less rain around April, October, and December; Balikpapan is calmer from June through October; and Medan splits its calmer stretch across February to April and June to July.
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Sulawesi (Makassar)
Makassar runs on a sharper pattern than its equatorial neighbors: a genuine wet season from November to April, driven hard by its exposure to the northwest monsoon on the island's western side, and a genuinely dry one from June to September.
Makassar
Bali
Surabaya
Jakarta
Flores
Lombok
Balikpapan
Bandung
Medan
Padang
Frequently asked questions
Does Indonesia have one monsoon season?
No. Bali, Lombok, and Flores share a similar rainy season from November to March and dry season from June to September. Java, further west, sees a longer rainy season, October or November to May. Padang, Balikpapan, and Medan, closer to the equator on Sumatra and Kalimantan, have no real dry season at all, while Makassar, on Sulawesi, has its own sharp wet-dry split, November to April rainy, June to September dry.
What is the best time to visit Indonesia overall?
June through September is historically the best window across most of this dataset, Bali, Lombok, Flores, Java, and Makassar alike, with August the driest month in several of these cities. Padang, Balikpapan, and Medan run on their own, less clearly defined calmer stretches instead, since none of the three has a true dry season.
Do cyclones affect Indonesia?
It depends where. Bali, Lombok, and Flores can occasionally be brushed by cyclones passing to the south, most often January to mid-April, while Java, Sumatra, Kalimantan, and Sulawesi, all closer to the equator, are not directly affected by tropical cyclones.
Why is Java's rainy season longer than Bali's?
Java sits further west, giving Jakarta, Bandung, and Surabaya a longer rainy season, October or November through May, compared to Bali, Lombok, and Flores's shorter November-to-March window.
Which Indonesian city in this dataset has no dry season?
Padang, on Sumatra, Balikpapan, on Kalimantan, and Medan, also on Sumatra, all see substantial rain in every month of the year, with no stretch that qualifies as a true dry season the way Bali, Java, or Makassar each have.
Is Makassar different from other Indonesian cities at a similar latitude?
Yes. Despite sitting close to the equator like Padang, Balikpapan, and Medan, Makassar has a genuine, sharply defined wet and dry season, driven by its exposure to the northwest monsoon on Sulawesi's western coast.