Warming Oceans Blamed as Deadly Floods Devastate Sri Lanka, Indonesia, Thailand, and Malaysia

A series of catastrophic floods and landslides across Sri Lanka, Indonesia, Thailand, and Malaysia has left more than 1,600 people dead and millions affected, with climate scientists confirming that unusually warm ocean temperatures played a decisive role in intensifying the storms that triggered the destruction.

The extreme rainfall, driven by Cyclones Ditwah and Senyar in late November, produced some of the deadliest weather events South and Southeast Asia have seen in recent years. Entire towns were submerged, hillsides collapsed, and critical infrastructure was swept away as the storms tore across the region.

A Climate-Driven Disaster

A rapid analysis by the World Weather Attribution (WWA) group found that sea surface temperatures in the North Indian Ocean were 0.2°C higher than the 30-year average, providing additional heat and moisture that supercharged the cyclones. Without global warming, researchers estimate the ocean would have been about 1°C cooler, significantly reducing the storms’ intensity.

“When the atmosphere warms, it can hold more moisture. As a result, it rains more in a warmer atmosphere,” said Mariam Zachariah of Imperial College London, one of the study’s authors.

The world is now 1.3°C warmer than pre-industrial levels, according to the U.S. National Oceanic and Atmospheric Administration, creating conditions ripe for extreme rainfall events across the tropics.

Sri Lanka: Floodwaters Reached Second Floors

Sri Lanka experienced some of the most severe impacts. Floodwaters in parts of the Central Province rose to the second floor of buildings, while landslides buried homes and roads. Cyclone Ditwah alone killed more than 600 people in Sri Lanka, with hundreds still missing.

“It rains a lot here, but never like this,” said Shanmugavadivu Arunachalam, a schoolteacher in Hatton. “Every region of Sri Lanka has been affected, and our region has been the worst impacted”.

Hydrologists reported that Sri Lanka received nearly 13 billion cubic meters of water in just 24 hours on November 28 — an amount equal to 10% of the country’s annual rainfall, overwhelming already saturated soil and triggering massive runoff and landslides.

Indonesia, Thailand, and Malaysia: Forest Loss and Urbanisation Worsened Impacts

In Indonesia’s Sumatra region, deforestation accelerated runoff, worsening floods that swept through villages and agricultural land. Malaysia and Thailand also saw widespread inundation as Cyclone Senyar made landfall, destroying homes, roads, and bridges.

WWA researchers found that five-day heavy rainfall events in the affected regions have become 28% to 160% more intense in recent years due to global warming.

Millions Displaced, Children Hit Hardest

Across the region, nearly 11 million people have been affected, with 1.2 million displaced into temporary shelters, according to UN assessments. Children have borne a disproportionate share of the crisis, with more than 4.1 million students experiencing school closures and disruptions to basic services.

“Children are sitting at the frontline of the climate crisis,” said UNICEF Deputy Spokesperson Ricardo Pires. “Extreme weather is becoming more frequent, more intense, and less predictable”.

A Warning for the Future

Scientists emphasize that while monsoon rains are normal, the scale and intensity of these storms represent a dangerous new pattern.

“What is not normal is the growing intensity of these storms,” said Dr. Sarah Kew of the Royal Netherlands Meteorological Institute, lead author of the WWA study.

Experts warn that without rapid global action to reduce emissions and strengthen climate resilience, such disasters will become increasingly common — and increasingly deadly.