In Pakistan's north-western Buner district, authorities say as many as 300 people were killed after a cloudburst unleashed torrents of rain that triggered landslides, flash floods and mudflows. Entire villages were reduced to rubble as boulders tumbled from steep slopes, crushing homes in their path.
Across the border in India, the Himalayan state of Uttarakhand was hit earlier this month. Local television footage showed a wall of floodwater racing down into the village of Dharali. The region has a grim history: in 2013, a catastrophic cloudburst claimed more than 6,000 lives and devastated thousands of villages.
What exactly is a cloudburst?
Meteorologists describe cloudbursts as highly localised weather events in which more than 100 millimetres of rain can fall within an hour over an area as small as 30 square kilometres. Often likened to a "rain bomb", these storms release the contents of an entire cloud in a matter of minutes.
The process is fuelled by warm, moisture-heavy air forced upward by mountain slopes. Clouds trapped by ridges and strong air currents hold vast amounts of water until they suddenly collapse, releasing torrential rainfall. The combination of moisture, mountains and monsoon winds makes India and Pakistan particularly vulnerable.
A rising threat in South Asia
Scientists say cloudbursts are becoming more frequent as a warmer atmosphere holds greater amounts of water. Every degree Celsius of warming allows the air to retain about seven per cent more moisture, increasing the risk of sudden, intense downpours.
The shifting patterns of the South Asian monsoon also play a role. Traditionally spread over months, rainfall is now arriving in shorter, more violent bursts. Instead of steady showers, countries are experiencing a cycle of intense floods followed by prolonged dry spells.
"Rising global temperatures have supercharged the hydrologic cycle, leading to more erratic and destructive rainfall," said Khalid Khan, a former Pakistani climate official. "What used to be rare events are now becoming disturbingly common."
Difficult to predict, hard to escape
Despite improvements in forecasting, experts acknowledge there is no reliable system to predict the exact time and location of a cloudburst. In Buner, early warning systems were in place but the downpour struck too suddenly for residents to evacuate.
Community groups like SOST in northern Pakistan say precautions can still reduce risks: avoiding construction near riverbanks, delaying travel to mountain areas during heavy rain, preparing emergency kits, and expanding forest cover to absorb runoff.
Climate change magnifying the danger
The destructive impact of these events is compounded by deforestation, rapid urbanisation and fragile mountain infrastructure. Melting glaciers in the Himalayas and Karakoram are also disrupting regional weather patterns, adding further unpredictability.
For mountain communities across South Asia, the consequences are existential. Beyond the immediate loss of life, flash floods destroy farmland, sweep away livestock and erase entire settlements.
As experts warn, the combination of climate change and unplanned development is turning once rare natural disasters into a recurring threat — with each new cloudburst leaving scars that may never fully heal.