OVERVIEW: From 5 October 2025, Tropical Cyclone MATMO (locally Storm No. 11), approached towards the northern provinces of Viet Nam from the East Sea. MATMO’s wide influence extended to several provinces in the Northern Region, areas which have been severely affected by Tropical Cyclone BUALOI (locally Storm No. 10), most of which have remained inundated by widespread flooding caused by successive tropical cyclones since September 2025. Persistent heavy rains and strong winds associated with the tropical cyclones, particularly Tropical Cyclone BUALOI have caused widespread impacts in the Northern and Central Regions. These impacts have not yet receded when the effects of Tropical Cyclone MATMO impacted the Northern Region, further compounding the situation and leading to even more devastating impacts.
CURRENT SITUATION: According to VDDMA’s Report on 9 October 2025 at 0600H UTC+7:
- Water Level Status of Rivers in the Northern region
- Cau River: The flood level at Gia Bay (Thai Nguyen) peaked at on 8 October 2025, exceeding the historical level by more than 1m. On the same day, water level at Huu Lung (Lang Son) peaked and exceeded the historical flood level by 1.77m. Water level is currently decreasing.
- Thuong River: The flood level at Cau Son (Bac Ninh) peaked on 9 October at 18.37m, on LV3 by 2.37m, at Phu Lang Thuong peaked at 03:00/09/10 at 7.60m, exceeding the LS Flood of 1986 (7.52m) by 0.08m. Currently, the flood in the lower reaches of the Cau River (Bac Ninh) is rising.
- Ca Lo River (Hanoi) at Manh Tan is 9.28m, 1.28m above LV3.
- Day River (Ninh Binh) at Phu Ly is 3.94m, 0.06m below LV3.
- Water Level Status of the Mekong Delta
- The water level at the upstream of the Mekong River is rising.
FORECAST: According to VDDMA Report as of 9 October 2025 0600H UTC+7: In the next 12-24 hours, flood on Thuong River at Cau Son and Phu Lang Thuong, flood on Trung River at Huu Lung, flood on Cau River at Gia Bay will continue to decrease; flood on Cau River at Dap Cau will continue to rise above level LV3 and is likely to peak on the afternoon of 9 October 2025.
ANTIPICATED RISKS:
- La Niña Alert: Most climate models combined with expert judgements suggest 70% chance of La Niña forming in October-December (OND) 2025 season and is likely to persist until December 2025 – February 2026 (DJF 2025-26) season (PAGASA). With this development, ENSO Alert and Warning System is now raised to possibility to La Niña.
- Tropical Cyclone Threat Potential: According to PAGASA, model forecasts indicate that in the week of 8-14 October 2025, a tropical cyclone like vortex may develop from the Philippines Sea and track towards the Viet Nam East Sea. According to NCHMF, during the period of August 2025 – January 2026, it is forecasted that around 8–11 storms or tropical depressions will form in the East Sea, of which 4–5 may affect the mainland. Storm activity is expected to concentrate in the latter half of the typhoon season, with Central Vietnam likely to be the most affected region. There is also a possibility of a storm or tropical depression forming over the southern East Sea in January 2026. ECMWF charts indicate a probability that this TC-like vortex may extend to Northern Viet Nam in the succeeding week. Currently, the likelihood of tropical cyclone formation for this forecast period is low.
IMPACTS:
As of 9 October 2025 0600H UTC+7, the VDDMA reported the following impacts of Tropical Cyclone MATMO in Viet Nam:
- 10 fatalities, 5 missing persons, 7 injuries
- 222,856 houses were flooded
- 711 houses were damaged or severely damaged
- About 83,738 houses are currently flooded
- Over 22,951 hectares of rice and crops were flooded and damaged; 2,288 livestock, 357,235 poultry were killed and swept away.
- Trains on the Hanoi – Dong Dang railway line were stopped; many national highways, provincial roads, and rural traffic routes were deeply flooded, cut off, causing traffic jams.
- On 7 October 2025, a hydroelectric dam collapse occurred at Bac Khe 1 hydroelectric dam in Tan Tien commune, Lang Son province. The Provincial People’s Committee established a working group to go to the scene and directed the communes to coordinate with the military and police forces to evacuate 803 households from areas at risk of flooding and landslides to safe places. A total of 196 households/779 people were directly affected by the dam collapse incident.
As of 5 October 2025 0600H UTC+7, the VDDMA reported the following impacts of Tropical Cyclone BUALOI in Viet Nam:
- 56 fatalities, 11 people missing, and 172 people injured
- 389 houses collapsed and 179,881 houses damaged
- The total preliminary economic loss in some provinces are approximately 713 billion USD (18,803 billion VND)
PREPAREDNESS AND RESPONSE:
- On 8 October 2025, 4 working delegations led by the Prime Minister and Deputy Prime Ministers inspected the flood response work in Thai Nguyen, Bac Ninh, Cao Bang and Lang Son provinces. The Prime Minister issued Decision No. 2221/QD-TTg to provide emergency support of 140 billion VND from the central budget reserve in 2025 to promptly provide relief, support people and overcome the consequences of floods.
- On 8 October 2025, the National Civil Defense Steering Committee issued Official Dispatch No. 14/CD-BC?-BNNMT on proactively responding to exceptionally large floods on the Cau River and Thuong River.
- The Ministry of National Defense mobilized 11,131 officers/256 vehicles of all kinds to participate in overcoming the consequences of Tropical Cyclone MATMO and organized 5 flights to carry the Government and Ministry of National Defense’s working group to inspect in Cao Bang; transported 8 tons of goods including (dried food, instant noodles) to help isolated people in Van Nham, Tan Tien, Yen Binh, Tuan Son communes (Lang Son province).
- The Ministry of Public Security has mobilized 11,500 officers and soldiers in Thai Nguyen, Bac Ninh, Lang Son, and Cao Bang provinces to support the evacuation of people to safe places and overcome the consequences of floods after the tropical cyclone.
- VDDMA continues to lead the coordination of response efforts to the impacts of the successive tropical cyclones.
The AHA Centre will continue to monitor for further developments and issue necessary updates. The AHA Centre stands ready to support VDDMA Viet Nam and other Member States should the need arises.
DATA SOURCES
ASEAN Disaster Monitoring & Response System (DMRS), ASEAN Disaster Information Network (ADINet), ASEAN Specialised Meteorological Centre (ASMC);
Viet Nam: VDDMA, NCHMF;
Verified news media agencies
