The number of people known to have died after Cyclone Ditwah made landfall in Sri Lanka on 28 November 2025 has reached 219, making the storm the worst natural disaster to befall the nation since the Boxing Day Tsunami of 2004. A further 209 people are still recorded as missing since the storm, with 18 people listed as having been injured. About 2 million people (almost 10% of the population) are thought to have been affected in some way by the storm, with 4071 homes destroyed and 71 121 damaged by flooding and landslides, as has much of the island's infrastructure and agricultural land. Authorities in Sri Lanka are warning that there is still a high risk of landslides, as monsoon rains fall onto already soaked hillside soils. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.
Cyclone Ditwah was first detected as a tropical depression off the south coast of Sri Lanka by the Indian Meteorological Department on 26 November 2025. This depression increased in strength, becoming first a deep depression and then a cyclonic storm of 27 November. It crossed over Sri Lanka on the night of 28-29 November, bringing catastrophic levels of rainfall, then moved out over the Bay of Bengal. The storm continued to move northwatds along the Coromandel Coast, in the process bringing more flooding to the states of Tamil Nadu and Puducherry, which led to three Human and 149 Cattle deaths, as well as flooding much farmland, and damaging or destroying 234 homes. The storm weakened as it moved northward, eventually making landfall in Tamil Nadu as a low pressure system on 3 December.
Tropical storms are caused by the warming effect of the Sun over tropical seas. As the air warms it expands, causing a drop in air pressure, and rises, causing air from outside the area to rush in to replace it. If this happens over a sufficiently wide area, then the inrushing winds will be affected by centrifugal forces caused by the Earth's rotation (the Coriolis effect). This means that winds will be deflected clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere, eventually creating a large, rotating Tropical Storm. They have different names in different parts of the world, with those in the Indian Ocean being referred to as cylcones.
Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms.
Cyclone Ditwah is not considered to be a large storm, but has caused extensive damage due to the large volumes of water it dropped onto Sri Lanka. It has been estimated that the cost of repairing the infrastructure damage caused by the storm will be about US$7 billion, coupled with a loss of income from the destruction of the agricultural and tourism sectors. Sri Lanka had a gross domestic product of about US$99 billion in 2024, but suffers from high levels of government debt. In 2023 the country was obliged to borrow US$3 billion from the International Monetary Fund to help with debt servicing, after a period of economic contraction in 2022 which led inflation to reach 57%.
Sri Lanka is considered to have met the first United Nations' Millennium Development Goal, halving extreme poverty between 1990 and 2015, but 12% of the country is still considered to be living below the extreme poverty line, and 53% below the poverty line. While the country has made progress on growing its economy and lifting its people out of poverty, climatic events such as Cyclone Ditwah can set progress back significantly, and are predicted to become more common as the climate warms. Countries in the Global South are predicted to be particularly badly impacted by effects of global warming, despite having done little to cause the crisis; Sri Lanka is considered to have produced about 0.03% of global greenhouse gas emissions since the onset of the Industrial Revolution.
See also...
.png)
