During the forty-first week of 2025, a total of 26 disaster events were reported across the ASEAN region, including earthquakes, floods, landslides, storms, and wind-related incidents affecting Indonesia, Philippines, and Viet Nam. In addition, the Department of Disaster Prevention and Mitigation (DDPM) reported that the widespread flooding from Week 37 persisted in 15 provinces. In Indonesia, Badan Nasional Penanggulangan Bencana (BNPB) recorded floods, landslides, and wind-related disasters across South Sulawesi, Central Java, West Java, Banten, Riau, East Java, Central Papua, ad North Sumatra. In the Philippines, National Disaster Risk Reduction and Management Council (NDRRMC) reported floods, earthquakes, and landslides in Sarangani, Zamboanga del Norte, Bukidnon, and Davao Oriental, in addition to the earthquake in Cebu that was reported in Week 40. Due to the effects of Tropical Cyclone MATMO, as well as the M6.9 earthquake and subsequent landslides in Cebu. In Viet Nam, Viet Nam Disaster and Dyke Management Authority (VDDMA) reported disasters associated with Tropical Cyclone MATMO which affected the Northern and northern Central Regions.

HIGHLIGHT:

After affecting the Philippines in Week 40, Tropical Cyclone MATMO brought heavy rainfall and strong winds to the northern provinces of Viet Nam, which had already been severely impacted by successive storms since September. The compounding effects of these consecutive events and persistent heavy rainfall intensified the impacts of MATMO, triggering catastrophic floods and landslides that caused 16 deaths, two missing persons, and 15 injuries as reported by VDDMA. Damage reports indicate 1,714 houses damaged, over 234K houses flooded, nearly 32K hectares of rice fields and crops inundated, and 13K livestock along with over 685K poultry lost. The rapid rise of water level also caused a hydroelectric dam break. Authorities immediately evacuated 803 households to safety before the incident.

In the Philippines, a magnitude 7.4 earthquake, followed by a magnitude 6.8 aftershock, occurred offshore of Davao Oriental. As of 13 October 2025, 0700H (UTC+7), the PHIVOLCS has recorded over 1K aftershocks. According to the NDRRMC, the doublet earthquake and associated landslides have resulted in eight deaths, 403 injuries, and about 8.9K displacements, affecting approximately 520K people (132K families) across Davao and CARAGA Regions. Reported damages include around 2K houses (298 totally damaged), as well as nine bridges and 37 road sections affected. Data collection and assessments are still ongoing..

The AHA Centre continues to closely monitor these situation, in coordination with the affected and potentially affected ASEAN Member States, and stands ready to provide support 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 over Northern Viet Nam associated with the effects of TC MATMO. In addition, moderate to high average rainfall was also observed in Brunei Darussalam, Cambodia, Indonesia (Sumatra, Sulawesi, Kalimantan, Maluku, Papua), Lao PDR, Malaysia, Myanmar, Philippines, Thailand, and Viet Nam. As of 1300H UTC+7, INVEST 96W is being monitored about 2,115 km east of Southern Mindanao. According to PAGASA, the potential for this system to develop into a tropical cyclone within 24 hours is MEDIUM.

GEOPHYSICAL:

Thirteen (13) 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 Sinabung (alert level II), Marapi (alert level II), Dempo (alert level II), Anak Krakatau (alert level II), Slamet (alert level II), Merapi (alert level III), Semeru (alert level II), Bromo (alert level II), Raung (alert level II), Lewotobi Laki-Laki (alert level III), Ili Lewotolok (alert level III), Soputan (alert level II), Lokon (alert level III), Ruang (alert level II), Gamalama (alert level II), 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, wetter conditions are predicted over much of the central and southern Maritime Continent. There is a small increase in chance of very heavy rainfall over parts of northeastern Mainland Southeast Asia, including parts of northern Viet Nam, northern Lao PDR, and northern Thailand. There is also a small increase in chance of very heavy rainfall over parts of the southern Maritime Continent, including parts of Java and Nusa Tenggara. A negative IOD is currently present. Models predict potential for La Niña conditions in the coming months.

Sources:

ASEAN Disaster Monitoring & Response System (DMRS); ASEAN Specialised Meteorological Centre (ASMC); Joint Typhoon Warning Centre (JTWC);

ASEAN Weekly Disaster Update Week 41 | 6 - 12 October 2025