REGIONAL SUMMARY:
During the thirty-fifth week of 2025, a total of 35 disaster events were recorded across ASEAN region, including tropical cyclones, floods, landslides, storms, and wind-related incidents affecting Indonesia, Myanmar, the Philippines, Thailand, and Viet Nam. In Indonesia, Badan Nasional Penanggulangan Bencana (BNPB) reported incidents in North Sulawesi, West Java, North Maluku, North Sumatra, Lampung, Banten, Bengkulu, Jakarta, and Central Sulawesi. In Myanmar, the Department of Disaster Management (DDM) reported impacts of flooding associated with Tropical Cyclone KAJIKI in Nay Pyi Taw. In the Philippines, the National Disaster Risk Reduction and Management Council (NDRRMC) reported flooding and landslides in Regions IVA, IVB, V, IX, XII, XIII, and BARMM, caused by Invest 93W (which developed to Tropical Cyclone NONGFA) and the Southwest Monsoon. Meanwhile, in Thailand, the Department of Disaster Prevention and Mitigation (DDPM) reported flooding and landslides across Lampang, Phetchabun, Kalasin, Nong Bua Lamphu, Khon Kaen, Phuket, Chiang Rai, Phayao, Nan, Phrae, Lampang, Lamphun, Chiang Mai, Mae Hong Son, Uttaradit, Sukhothai, Phitsanulok, Loei, and Nakhon Phanom due to Tropical Cyclones KAJIKI and NONGFA. In Viet Nam, Disaster and Dyke Management Authority (VDDMA) reported flooding, landslides, and storms associated with Tropical Cyclone NONGFA affecting Northern and Central Regions.
HIGHLIGHT:
Tropical Cyclone KAJIKI, which formed in the Philippines in Week 34, tracked westward and intensified into a typhoon before making landfall along the Nghe An – Ha Tinh coasts in Viet Nam on 25 August. TC KAJIKI brought torrential rains and damaging winds causing widespread impacts across Central and Northern Viet Nam as reported by VDDMA Viet Nam. Impacts were also reported by DDPM in 14 provinces in Thailand and by DDM in Nay Pyi Taw, Myanmar. In the same week, the low pressure area INVEST 93W caused widespread floods in the Philippines before developing into Tropical cyclone NONGFA which also made landfall over the coasts of Ha Tinh – Quang Tri, Viet Nam. Significant impacts were reported by DDPM Thailand and VDDMA Viet Nam. As of 1 September 2025, the combined effects of these tropical systems resulted in 15 deaths, 62 injuries, 5 missing persons, and more than 394K affected people, and 138K displaced. Authorities across the region are leading response operations and damage assessments to support affected communities. The AHA Centre continues to closely monitor the situation and remains in close coordination with affected and potentially affected ASEAN Member States, stands ready to provide support if required.
HYDRO-METEO-CLIMATOLOGICAL:
For the past week, data from the ASEAN Specialised Meteorological Centre (ASMC) indicated high 7-day average rainfall concentrated across Brunei Darussalam, Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, the Philippines, Singapore, Thailand, and Viet Nam. Tropical Cyclones KAJIKI and NONGFA affected the region. In addition another Low Pressure Area (INVEST 95W) is being observed East of Luzon in the Philippines, and is being closely monitored for potential development into a significant tropical cyclone (PAGASA, JTWC).
GEOPHYSICAL:
Five (5) significant earthquakes (M>5.0) were recorded by Indonesia’s Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) and Myanmar’s Department of Meteorology and Hydrology (DMH). Mount Sinabung (alert level II), Sorikmarapi (alert level I), Tandikat (alert level I), Marapi (alert level II), Dempo (alert level II), Anak Krakatau (alert level II), Tangkuban Parahu (alert level I), Slamet (alert level II), Merapi (alert level III), Semeru (alert level II), Bromo (alert level II), Raung (alert level II), Sangeangapi (alert level I), Lewotobi Laki Laki (alert level III), Sirung (alert level I), Ili Lewotolok (alert level III), Soputan (alert level II), Lokon (alert level II), Ruang (alert level II), Awu (alert level II), Gamalama (alert level II), Ibu (alert level II), and Dukono (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 the Philippines Institute of Volcanology and Seismology (PHIVOLCS)..
OUTLOOK:
According to the ASEAN Specialised Meteorological Centre (ASMC), for the coming week, no significant regional temperature anomalies are predicted. There is a small increase in extreme hot conditions predicted over parts of the northwestern and southern Maritime Continent, in particular Peninsular Malaysia, northern Sumatra, and Java. While ENSO neutral conditions have been present, models predict potential for La Niña conditions to develop in the coming months.
Sources:
ASEAN Disaster Monitoring & Response System (DMRS); ASEAN Specialised Meteorological Centre (ASMC); Joint Typhoon Warning Centre (JTWC);
Indonesia: BNPB, BMKG, PVMBG;
Myanmar: DDM, DMH;
Philippines: NDRRMC, PAGASA, PHIVOLCS;
Thailand: DDPM, TMD;
Viet Nam: VDDMA, NCHMF;
Various news agencies.
