When the sky breaks: Monsoon floods and extreme rainfall in South Asia

In the summer of 2025, Pakistan experienced a devastating series of monsoon floods. A study by World Weather Attribution confirmed that climate change has increased rainfall by an estimated 10 to 15 percent. This intensification had immediate consequences: houses were destroyed, people died, and entire neighborhoods were submerged. The Punjab and Khyber Pakhtunkhwa regions were particularly hard hit. In Rawalpindi, over 230 millimeters of rain fell in a single day on July 17, causing the city's drainage system to collapse. Even in mountainous regions like Gilgit-Baltistan, the extreme weather led to catastrophic events, including an avalanche that buried a group of volunteers.

At the same time, other parts of Asia also experienced exceptional rainfall. Hong Kong recorded its heaviest August rainfall since weather records began in 1884, with more than 350 millimeters falling in a single day. Within just eight days, four so-called "black rainstorm warnings" had to be issued there – a historic record. In northern India, particularly in the state of Uttarakhand, there were severe floods, landslides, and widespread destruction, resulting in numerous deaths and leaving many people missing.

These events are no coincidence. A warmer atmosphere can hold more moisture, leading to more frequent and intense rainfall. Every additional warming of the air increases its water-holding capacity, making rainfall more extreme. In Pakistan, a spring heat wave also contributed to the intensification of monsoon rains: The temperature rise led to a strong thermal low pressure that attracted moist air masses. At the same time, snowmelt in the high mountains began earlier, causing rivers and reservoirs to swell even before the start of the rainy season.

Scientific evidence clearly indicates that climate change is making extreme rainfall events like this year's more likely and intense. The combination of heat, melting glaciers, and inadequate infrastructure in rapidly growing cities significantly increases the vulnerability of many regions. Particularly alarming is the fact that countries like Pakistan, which account for less than one percent of global CO₂ emissions, are among the hardest hit by these climate-related extreme events.

If such disasters are not to become the new normal, urgent investments are needed in climate-resilient infrastructure, efficient early warning systems, and sustainable urban planning. Adapting to a changing climate reality is no longer just a matter of precaution, but of immediate survival – especially for regions that have contributed least to climate change but are feeling its effects most acutely.

glossary

Attribution Studies : Scientific investigations that determine the extent to which climate change has made a particular weather event more likely or more intense.
Black Rainstorm Warning : A warning signal issued by the authorities in Hong Kong for extreme rainfall, the highest of three warning levels.
Monsoon hydrology : The field of hydrology that deals with the effects of the monsoon on rivers, soils and water systems.
Thermal depression : An area of ​​low air pressure caused by strong heating of the air, which attracts moist air masses.
Climate adaptation : Measures taken to limit the negative consequences of climate change and increase the resilience of societies and ecosystems.