Very Strong El Nino: Java Under Alert as BMKG Issues Latest Warning
The Indonesian Meteorological, Climatological, and Geophysical Agency (BMKG) has stated that the current El Nino is occurring with very high intensity. This was revealed in the Atmospheric Dynamics Analysis for the first ten-day period of September 2026, released by BMKG on 14 September 2026.
Monitoring results for the first ten days of September 2026 show the Indian Ocean Dipole (IOD) index at +0.394, an increase from the August IOD which was also positive at 0.376. Meanwhile, the Sea Surface Temperature Anomaly (SSTA) value in the Nino 3.4 region for this period was +2.76, a decrease from August’s +2.83. The ENSO index (3-month average) for July-August-September stands at 2.6.
For context, IOD and ENSO are two indices that indicate sea surface temperature conditions in the Pacific Ocean (ENSO) and the Indian Ocean (IOD), which influence weather conditions in Indonesia. ENSO has three main phases: warm (El Nino), Neutral, and cold (La Nina). Similarly, the IOD has phases. El Nino can trigger hot weather and drought in Indonesia, while a positive IOD can also cause reduced rainfall.
While these temperature anomalies are significant, BMKG noted that Indonesia’s climate is also shaped by other factors. “BMKG predicts that El Nino 2026 will persist until early 2027. Additionally, the IOD index is likely to remain in a positive phase until the beginning of 2027,” BMKG wrote.
Level 1 Drought Disaster Alert
BMKG has issued an early warning for meteorological drought applicable for the second ten-day period of September 2026, with the following classifications:
Alert: Several regencies in the provinces of Bali, South Kalimantan, Central Kalimantan, East Kalimantan, Riau Islands, North Maluku, East Nusa Tenggara, South Papua, Southeast Sulawesi, and South Sumatra.
Watch: Several regencies in the provinces of Gorontalo, West Java, Central Java, South Kalimantan, Central Kalimantan, East Kalimantan, Bangka Belitung Islands, Riau Islands, Lampung, Maluku, North Maluku, West Nusa Tenggara, East Nusa Tenggara, West Sulawesi, South Sulawesi, Central Sulawesi, Southeast Sulawesi, North Sulawesi, and South Sumatra.
Warning: Several regencies in the provinces of Bali, Banten, DKI Jakarta, Gorontalo, West Java, Central Java, West Kalimantan, South Kalimantan, Central Kalimantan, Bangka Belitung Islands, Riau Islands, Maluku, North Maluku, West Nusa Tenggara, East Nusa Tenggara, South Papua, West Sulawesi, South Sulawesi, Central Sulawesi, Southeast Sulawesi, North Sulawesi, and South Sumatra; as well as the entire provinces of DI Yogyakarta and East Java.
“Rainfall during the first ten days of September varied between High (0.60%), Medium (6.77%), and Low (92.62%). Meanwhile, the nature of rainfall varied from Far Above Normal (2.37%), Above Normal (1.92%), Normal (2.85%), and Below Normal (92.86%),” BMKG added.
Days Without Rain
BMKG noted that regions in Indonesia are currently experiencing days without rain ranging from very short to extremely long. It was reported that 384 points are experiencing long periods without rain (21-30 consecutive days), 872 locations are experiencing very long periods (31-60 consecutive days), and 1,637 points are experiencing extremely long periods (more than 60 consecutive days). The longest period without rain was reported at the BPP Pajangan rain gauge in Bantul, DI Yogyakarta, lasting 131 consecutive days.
Almost All of Indonesia Experiencing Dry Season
BMKG recorded that 80.7% of Indonesia’s territory (564 Seasonal Zones/ZOM) is currently experiencing the dry season. Regions currently in the dry season include parts of Aceh, most of North Sumatra, West Sumatra, Riau, Riau Islands, Bengkulu, Jambi, South Sumatra, Bangka Belitung Islands, Lampung, Banten, DKI Jakarta, West Java, Central Java, DI Yogyakarta, East Java, West Kalimantan, Central Kalimantan, South Kalimantan, East Kalimantan, North Kalimantan, Bali, West Nusa Tenggara, East Nusatinga, North Sulawesi, Gorontalo, Central Sulawesi, West Sulawesi, South Sulawesi, Southeast Sulawesi, Maluku, North Maluku, Papua, West Papua, Southwest Papua, Central Papua, Papua Highlands, and South Papua.