REGIONAL SUMMARY:
During Week 49 of 2025, a total of 32 disaster events were reported across the ASEAN region, including floods, landslides, storms, and wind-related incidents affecting Indonesia, the Philippines, and Viet Nam. In Indonesia, Badan Nasional Penanggulangan Bencana (BNPB) recorded multiple events across Lampung, East Java, North Maluku, West Nusa Tenggara, Gorontalo, West Java, Central Java, Central Sulawesi, and Banten. Meanwhile, in the Philippines, the National Disaster Risk Reduction and Management Council (NDRRMC) reported flooding in MIMAROPA, Regions V, VI, VII, VIII, and CARAGA. In Viet Nam, landslides and flooding in Lam Dong were reported by the Viet Nam Disaster and Dyke Management Authority (VDDMA). Additionally, since Week 47, both Thailand’s Department of Disaster Prevention and Mitigation (DDPM) and Indonesia’s BNPB have reported severe flooding in southern Thailand and northern parts of Sumatra, respectively, following the effects of the Northeast Monsoon and Tropical Cyclone SENYAR.
HIGHLIGHT:
The combined influence of the Northeast Monsoon, the Shear Line, and the development of Tropical Cyclone Wilma (INVEST 93W) brought significant rainfall to the Philippines, triggering flooding across MIMAROPA, Regions V, VI, VII, VIII, and CARAGA. As of 8 Dec (0700H UTC+7), the NDRRMC reported 132.8K affected people (57.6K families), with 22.7K displaced, including 13.9K individuals served in 102 evacuation centres. Flooding also caused damage to infrastructure, with three houses partially damaged, 15 roads affected (seven still impassable), and 31 areas remaining inundated.
In Indonesia, the severe flooding and landslides across northern parts of Sumatra (North Sumatra, Aceh, and West Sumatra) from Week 47 caused extensive humanitarian and infrastructure impacts. According to BNPB, as of 8 Dec at 1700H, the disaster caused 961 deaths, 293 missing, and 5K injured, while damaging 157.6K houses and hundreds of critical infrastructure: 199 health facilities, 534 educational facilities, 425 places of worship, 234 office buildings, 497 bridges, and 1.2K other public facilities.
Authorities have activated emergency response operations, including evacuations, relief distribution, and restoration of essential services. Damage assessments and clearing efforts are ongoing to support affected communities. The AHA Centre continues to closely monitor the situation, in coordination with BNPB Indonesia and NDRRMC Philippines, 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 (Sarawak and Sabah), the Philippines, Timor Leste, and parts of Central Viet Nam. Significantly high average rainfall observed in the Philippines was primarily associated with the Northeast Monsoon, the Shear Line, and the development of Tropical Cyclone WILMA. As of 8 Dec at 1700H UTC+7, INVEST 91S, located approximately 974 km west southwest of Bengkulu in Indonesia, is currently under monitoring for potential development (BMKG).
GEOPHYSICAL:
Six (6) significant earthquakes (M>5.0) were recorded by Indonesia’s Badan Meteorologi, Klimatologi, dan Geofisika (BMKG). 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 Philippines Institute of Volcanology and Seismology (PHIVOLCS).
OUTLOOK:
According to the ASEAN Specialised Meteorological Centre (ASMC), for the coming week, Wetter conditions are expected over eastern Mainland Southeast Asia and parts of the northeastern and southeastern Maritime Continent, while much of the remaining Maritime Continent is likely to be drier and cooler than usual. There is a small increased chance of very heavy rainfall along eastern Mainland Southeast Asia and parts of the southern Maritime Continent. The negative IOD is weakening, and La Niña conditions, expected to persist until Jan–Feb 2026, typically bring wetter-than-average rainfall across much of the region during December – February.
Sources:
ASEAN Disaster Monitoring & Response System (DMRS); ASEAN Specialised Meteorological Centre (ASMC); Joint Typhoon Warning Centre (JTWC);
Indonesia: BNPB, BMKG, PVMBG;
Philippines: NDRRMC, PHIVOLCS;
Thailand: DDPM;
Viet Nam: VDDMA;
Various news agencies.
