The Latest on Southeast Asia: Severe Flooding in Southeast Asia

Since mid-November, three unusually late-season cyclones and intensified monsoon systems have devastated South and Southeast Asia, impacting Sri Lanka, Indonesia, Thailand, Malaysia, and Vietnam. The intense string of storms have killed at least 1,350 people across the region and have left millions displaced. The La-Niña-intensified storms are the latest disasters to strike the region, following deadly typhoons and an earthquake that devastated the region, particularly the Philippines and Vietnam, just months prior.  

Tropical Cyclone Senyar descended on Indonesia’s Aceh, North Sumatra, and West Sumatra provinces from November 22 to 25, triggering deadly floods and landslides across dozens of districts. The floods and landslides have killed over 950 people, with 274 people still missing. Over 1 million people have been displaced with more than 900,000 living in temporary shelters. The Indonesian government, which faces domestic criticism for slow response and refusing outside assistance, has said that Sumatra requires $3.11 billion in reconstruction and recovery funds. President Prabowo Subianto has announced the country will purchase 200 helicopters in 2026 to increase defense and natural disaster preparedness.  

Intense monsoon rains have devastated southern Thailand, causing intense flooding across 12 provinces. At least 276 people were killed, 5,000 injured, and over 219,000 residents displaced. The flooding also hit northern Malaysia, killing at least two people and leaving 18,700 displaced. The Thai government announced it had disbursed over $31.3 million in compensation to more than 120,000 households, and that recovery efforts have restored water and electricity to almost all the affected areas. Concurrently, Cyclone Ditwah hit Sri Lanka, killing at least 618 and leaving 209 missing. 

Central Vietnam has faced relentless downpours since mid-November, which was worsened by Typhoon Koto, killing at least 98 people and leaving 12 missing. The Vietnamese government confirmed that more than 186,000 homes were damaged and 3 million livestock were swept away. Vietnam has faced one of its harshest typhoon seasons in years, with Typhoon Koto marking the country’s 15th to strike the country this year. In 2025, Vietnam’s storms and floods have caused more than 400 deaths, 700 injuries, and over $3.2 billion in economic losses.  

On November 17, the U.S. embassy in Vietnam provided $500,000 to deliver immediate relief to families and individuals impacted by the successive typhoons. To further support Vietnam’s recovery, the United Nations has allocated $2.6 million in aid from the UN Central Emergency Response Fund. The Department of State has also extended its condolences to those impacted by the flooding in Indonesia, Malaysia, and Thailand, standing ready to support recovery efforts. The European Union released $2.8 million in emergency assistance to aid the impacted communities in Sri Lanka, Indonesia and Thailand. 

Lauren Mai is a Program Manager and Research Associate for the Southeast Asia Program at CSIS. 

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