REGIONAL SUMMARY:
During the thirty-ninth week of 2026, a total of 23 disasters were reported across ASEAN, including droughts, floods, landslides, storms, and wind-related disasters in Cambodia, Indonesia, Malaysia, the Philippines, Thailand, and Viet Nam. In Cambodia, National Committee for Disaster Management (NCDM) reported flooding in Battambang. In Indonesia, Badan Nasional Penanggulangan Bencana (BNPB) reported droughts, floods, landslides, storms, and wind-related disasters across Aceh, East Java, West Kalimantan, South Kalimantan, Riau Islands, Lampung, East Nusa Tenggara, Central Sulawesi, Southeast Sulawesi, West Sumatra, and North Sumatra. In Malaysia, Agensi Pengurusan Bencana Negara (NADMA) reported floods and landslides in Pahang, Kelantan, and Selangor. In Thailand, flooding that began during Week 37 continued to be reported by Department of Disaster Prevention and Mitigation (DDPM), with impacts now recorded across 41 provinces and Bangkok. Lastly, Viet Nam Disaster and Dyke Management Authority (VDDMA) reported disasters in Lam Dong, Vinh Long, Dong Nai, Ca Mau, Nghe An, and Gia Lai.
HIGHLIGHT:
In Thailand, widespread flooding has affected 41 provinces and Bangkok since 16 Seo. According to DDPM, a total of 582.5K households (1.81 million people) were affected, with 8 fatalities reported in Sa Kaeo (5), Chanthaburi (2), and Saraburi (1). As of 28 Sep at 0600H UTC+7, flooding remains ongoing in 27 provinces and Bangkok, affecting approximately 576.4K households (1.79 million people) across 151 districts, 792 subdistricts, and 4,087 villages. Central and Eastern regions recorded the largest impacts, with 364.9K and 151.3K affected households, respectively. Flooding was primarily associated with heavy rainfall and overflowing rivers, with increased water levels reported in several areas.Relevant authorities, including DDPM, local authorities, military personnel, police, volunteers, and local organisations, have been conducting response operations, including evacuations, raising household belongings to higher ground, drainage operations, traffic management, and establishment of temporary shelters. The AHA Centre is closely monitoring the developments of widespread flooding in Thailand, in close coordination with DDPM, and stands ready to support should the need arise.
HYDRO-METEO-CLIMATOLOGICAL:
During the past week, data from the ASEAN Specialised Meteorological Centre (ASMC) indicated medium to high seven-day average rainfall across Brunei Darussalam, Cambodia, Indonesia (Sumatra and northern Kalimantan), southern Lao PDR, Malaysia, southern Myanmar, the Philippines, Thailand, and Viet Nam. As of this report, two tropical disturbances, Tropical Cyclone SURIGAE over the western Pacific Ocean and INVEST 92W over Myanmar, are being monitored for their potential impact on ASEAN Member States (DMRS, JTWC).
GEOPHYSICAL:
Three (3) significant earthquakes (M>5.0) were recorded by Indonesia’s Badan Meteorologi, Klimatologi, dan Geofisika (BMKG). Mount Ibu (alert level II), Semeru (alert level III), and Marapi (alert level II) in Indonesia, and Taal (alert level 1), Mayon (alert level 2), Bulusan (alert level 1), and Kanlaon (alert level 2) volcanoes in the Philippines reported recent volcanic activity according to Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and the Philippines Institute of Volcanology and Seismology (PHIVOLCS).
OUTLOOK:
According to the ASEAN Specialised Meteorological Centre (ASMC), for the coming week, drier than usual conditions are predicted over most of the southern ASEAN region, while drier than usual conditions are also predicted for parts of the northeastern Maritime Continent and southern Mainland Southeast Asia. Additionally, warmer than usual conditions are predicted over most of the ASEAN region. For regional assessment of extreme, there is a small increase in chance of very heavy rainfall conditions to occurs over parts of northern Mainland Southeast Asia. Meanwhile, a moderate increase in chance of extreme hot conditions is predicted over parts of southern and central Mainland Southeast Asia, including Cambodia and southern Viet Nam, as well as over the eastern parts of Borneo. A small increase in the chance of extreme hot conditions is also predicted over much of the western Maritime Continent and the northern half of the Philippines. The El Niño – Southern Oscillation (ENSO) monitoring system state is “El Niño Conditions”. Strong El Niño conditions are predicted until at least the end of 2026. El Niño at this time of the year, typically brings drier conditions for much of the Maritime Continent, and to a lesser extent, some parts of Mainland Southeast Asia.
Sources:
ASEAN Disaster Monitoring & Response System (DMRS); ASEAN Disaster Information Network (ADINet); ASEAN Specialised Meteorological Centre (ASMC); ASEAN Earthquake Information Centre (AEIC); Joint Typhoon Warning Centre (JTWC);
Cambodia: NCDM;
Indonesia: BNPB, BMKG, PVMBG;
Malaysia: NADMA;
Philippines: NDRRMC, PAGASA, PHIVOLCS;
Thailand: DDPM;
Viet Nam: VDDMA;
Various news agencies.
