Experts warn that thousands of people in Southeast Asia may be at risk of infection, disease and delayed access to health care after the tropical storms.[1] Tropical storms cause catastrophic flooding due to extreme rainfall from a combination of monsoon rains and thunderstorms.[1] By December 7, 2025, more than 1,500 people had died and extensive damage had occurred.[1] In Sri Lanka, this is the worst natural disaster in decades.[1] Storm Senyar hit Indonesia (the island of Sumatra), Malaysia and Thailand the most, where it claimed hundreds of lives.[1] Tropical storm Wipha caused great damage especially in the Philippines.[2] In July 2025, additional storms Wipha, Francisco and Co-may and caused widespread flooding in the northern Philippines.[4] Estimated cumulative rainfall for the 7 days through December 1 was extremely high over the affected areas.[1]