REGIONAL SUMMARY:
During Week 51 of 2025, a total of 23 disaster events were reported across the ASEAN region, including floods, landslides, storms, and wind-related incidents that affected Indonesia. According to the Badan Nasional Penanggulangan Bencana (BNPB), impacts were reported across East Java, South Kalimantan, Riau, Central Java, Banten, West Java, East Nusa Tenggara, Lampung, Jakarta, and West Nusa Tenggara. In addition, BNPB continued to report the updated impacts from the severe flooding in northern parts of Sumatra, following the effects of the Northeast Monsoon and Tropical Cyclone SENYAR from Week 47.
HIGHLIGHT:
According to BNPB, as of 22 Dec 2025, the total number of fatalities resulting from the widespread floods and landslides in Aceh, North Sumatra, and West Sumatra has reached 1,090 people, with 186 individuals still reported missing and around 7K people injured. The disaster has caused extensive damage to housing and public infrastructure, including 147.2K houses, 219 health facilities, 967 educational facilities, 434 places of worship, 290 office buildings, 145 bridges, and approximately 1.6K other public facilities.
Response and recovery efforts continue, with authorities accelerating housing construction and restoring access through infrastructure repairs. Health services and clean water distribution are being reinforced to support affected communities. The AHA Centre continues to closely monitor the situation, in coordination with BNPB Indonesia, and remains ready to provide assistance should the need arise.
HYDRO-METEO-CLIMATOLOGICAL:
For the past week, data from the ASEAN Specialised Meteorological Centre (ASMC) indicated medium to high 7-day average rainfall across Brunei Darussalam, Indonesia, Malaysia, the Philippines, and Timor-Leste, with high rainfall concentrated in the equatorial and southern equatorial regions. As of 1900H UTC+7, INVEST 93S (TC 09S) is being monitored about 988 km south of Bengkulu in Indonesia with high potential of strengthening into a tropical cyclone within 24 hours. (BMKG).
GEOPHYSICAL:
Five (5) significant earthquakes (M>5.0) were recorded by Indonesia’s Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) and the Philippines Institute of Volcanology and Seismology (PHIVOLCS). Mount Marapi (alert level II), Semeru (alert level III), and Ibu (alert level II) in Indonesia, and Kanlaon (alert level 2), Taal (alert level 1), Mayon (alert level 1), and Bulusan (alert level 1) volcanoes in the Philippines reported recent volcanic activity according to Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and PHIVOLCS.
OUTLOOK:
According to the ASEAN Specialised Meteorological Centre (ASMC), for the coming week, warmer-than-usual temperatures are forecast across much of the eastern and southern Maritime Continent, alongside a small increase in chance of very heavy rainfall in parts of the southern Maritime Continent, including Nusa Tenggara and Timor-Leste. La Niña conditions are present and expected to persist into January 2026, typically bringing wetter-than-average rainfall to Southeast Asia during the December–February period, while the negative Indian Ocean Dipole (IOD) has weakened, with neutral IOD conditions forecast by January 2026.
Sources:
ASEAN Disaster Monitoring & Response System (DMRS); ASEAN Specialised Meteorological Centre (ASMC); Joint Typhoon Warning Centre (JTWC);
Indonesia: BNPB, BMKG, PVMBG;
Philippines: PHIVOLCS;
Various news agencies.
