Cyclones Senyar and Ditwah Devastate Southeast Asia, Highlighting Climate Change's Role

In late November 2025, Southeast Asia faced unprecedented devastation as Tropical Cyclones Senyar and Ditwah unleashed catastrophic flooding and landslides, resulting in over 1,800 fatalities and displacing millions. Scientific analyses now confirm that climate change significantly amplified the severity of these storms, underscoring the urgent need for enhanced disaster preparedness and climate resilience strategies in the region.

Cyclone Senyar formed in the Strait of Malacca on November 25, 2025—a region that had not experienced such a storm in 135 years. The cyclone made landfall in northeastern Sumatra, Indonesia, causing severe flooding and landslides. The storm resulted in over 1,200 fatalities, including 969 in Sumatra, and necessitated at least $3 billion in relief efforts. (reuters.com)

Simultaneously, Cyclone Ditwah struck Sri Lanka on November 28, leading to extensive floods and landslides. The disaster claimed over 600 lives and caused economic losses estimated at around $7 billion. (reuters.com)

The World Weather Attribution (WWA) group conducted a rapid analysis and found that ocean temperatures warmed by human-caused climate change fed the intense rainfall that triggered deadly floods and landslides across Asia. During the most intensive five days of rainfall, sea surface temperatures in the North Indian Ocean were 0.2 degrees Celsius higher than the 1991–2020 average, providing additional heat and energy to the storms. Without the 1.3°C rise in global mean temperatures since the pre-industrial age, these sea temperatures would have been about 1°C cooler. (apnews.com)

Sarah Kew, a climate researcher at the Royal Netherlands Meteorological Institute, noted, "What is not normal is the growing intensity of these storms and how they are affecting millions of people and claiming hundreds of lives." (reuters.com)

The overlapping storms affected nearly 11 million people across the region, with about 1.2 million displaced into shelters. Infrastructure, including roads, utilities, and farmlands, suffered extensive damage. (worldweatherattribution.org)

In Sri Lanka, as of December 8, at least 635 fatalities, 192 missing, and over 600,000 families displaced were reported; 2.1 million individuals have overall been affected. For Indonesia, at least 593 fatalities, 468 missing, and 2,600 injured individuals, as well as 600,000 displaced people, have been reported by the International Federation of Red Cross and Red Crescent Societies (IFRC) as of December 2. (worldweatherattribution.org)

Cyclone Senyar's formation in the Strait of Malacca was a rare event, with the previous instance dating back to 1886. The Malacca Strait, bordered by Malaysia and Indonesia, typically lacks the atmospheric and oceanic conditions required for cyclogenesis. This anomaly highlights the changing patterns of tropical cyclone formation, potentially linked to climate change. (indiatoday.in)

The devastating impact of Cyclones Senyar and Ditwah serves as a stark reminder of the tangible consequences of climate change. As extreme weather events become more frequent and severe, it is imperative for Southeast Asia and the global community to invest in robust climate adaptation and mitigation strategies to safeguard vulnerable populations and infrastructure.