BMKG Releases Early Rainy Season Map for November-December; List of Affected Regions Provided
The Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) has released early forecast data for the start of the rainy season and predictions for its peak for the 2026/20lag7 period. The public is advised to remain vigilant regarding potential weather changes and to prepare for the transition and peak of the rainy season.
According to BMKG’s social media update on Friday (2/10/2026), the start of the rainy season will occur gradually during November and December. Approximately 24.66% of Indonesia’s territory is predicted to enter the early rainy season in November.
These regions include:
Parts of Sumatra
Parts of Java
Parts of Kalimantan
Parts of Bali
Parts of NTB
Small parts of NTT
Parts of Sulawesi
Parts of North Maluku
Parts of Maluku
Northern West Papua
Parts of South Papua
By December, an additional 17.31% of Indonesia’s territory is expected to enter the early rainy season, covering:
Parts of Lampung
Most of Java
Parts of South Kalimantan
Most of Bali
Most of NTB
Most of NTT
Most of Sulawesi
Parts of North Maluku
Parts of Maluku
Southern parts of South Papua
BMKG also predicts the peak of the 2026/2027 rainy season will be concentrated over three main months: December 2026, January 2027, and February 2027.
Approximately 36.94% of Indonesia’s territory is predicted to experience the peak of the rainy season in December 2026, including:
Most of Sumatra
Most of Kalimantan
Parts of North Sulawesi
Southern coast of Gorontala
Small parts of Central Sulawesi
Most of West Sulawesi
Small parts of Maluku
Western parts of Southwest Papua
Small parts of West Papua
Northern Papua
Eastern parts of Central Papua
Western parts of South Papua
The peak of the rainy season will expand to 25.68% of Indonesia’s territory in January 2027, specifically in:
Southern Riau
Central Riau Islands
Small parts of Jambi
Northern Bengkulu
Bangka Belitung Islands
Western South Sumatra
Northern Lampung
Parts of Java
Central Bali
Western NTB
Parts of NTT
West Kalimantan
Most of Central Kalimantan
Small parts of East Kalimantan
South Kalimantan
Parts of Sulawesi
Small parts of North Maluku
Western Maluku
Parts of Papua
Finally, 16.79% of the territory will enter the peak of the rainy season in February 2027, covering:
Central Lampung
Most of Java
Most of Bali
Most of NTB
Most of NTT
Southern West Sulawesi
Parts of South Sulawesi
Southern Southeast Sulawesi
Parts of Maluku
Most of Papua