Executive summary
Heavy monsoon rainfall across Pakistan in 2025 led to severe urban flooding that disrupted lives, infrastructure and economic activity. World Weather Attribution analysis finds that human-caused climate change increased the intensity of rainfall during the monsoon, amplifying flood risk in cities and towns. The study highlights how rapid urbanisation, inadequate drainage and high population density interacted with climate-amplified rainfall to produce severe impacts, particularly for highly exposed and vulnerable communities.
What happened
During the 2025 monsoon season, several regions of Pakistan experienced episodes of very heavy rainfall over short periods. Urban centres were particularly affected, as drainage systems were unable to cope with the volume and intensity of rain. Roads, homes and businesses were flooded, transport networks were disrupted and essential services were interrupted.
In many cities, flooding occurred repeatedly over the course of the season, limiting recovery between events and increasing cumulative damage. Informal settlements and low-lying neighbourhoods were among the hardest hit, with limited protection from floodwaters.
What the attribution analysis found
World Weather Attribution finds that climate change increased the intensity of monsoon rainfall in Pakistan. Warmer atmospheric conditions allowed more moisture to be carried by monsoon systems, resulting in heavier downpours when storms developed.
The analysis shows that rainfall of the intensity observed in 2025 has become more likely in today’s climate compared with a pre-industrial baseline. While monsoon variability remains high, the influence of warming on extreme rainfall is clear and consistent with broader regional evidence.
As rainfall intensity increases, the probability of urban flooding rises sharply, particularly where drainage capacity has not kept pace with growing hazard levels.
Urban exposure and vulnerability
The study highlights that impacts were driven not only by rainfall intensity but also by high exposure and vulnerability. Rapid urban growth has expanded development into flood-prone areas, while drainage and waste management systems have struggled to keep pace with population growth.
Socio-economic factors further increased risk. Lower-income households often live in the most flood-exposed areas and have limited resources to recover, meaning similar flood depths result in very different outcomes across communities.
How climate attribution fits into flood risk reporting
Climate attribution clarifies how climate change is altering monsoon rainfall characteristics, even where seasonal rainfall totals remain uncertain. By showing that extreme rainfall is intensifying, attribution provides a stronger basis for reassessing urban flood risk beyond historical records.
This is particularly important for cities where past flood experience no longer reflects current or future hazard levels.
Why this matters for organisations
For municipal authorities, utilities, insurers and businesses operating in Pakistan’s cities, the findings underline growing exposure to flood-related disruption. Transport systems, supply chains and essential services are increasingly vulnerable to intense rainfall events that exceed design assumptions.
How to use this in your own risk work
Organisations should incorporate climate-adjusted rainfall intensity projections into urban flood assessments, review drainage and asset capacity under extreme rainfall scenarios, and map exposure across vulnerable communities. Strengthening early warning, drainage maintenance and inclusive recovery planning will be critical to reducing future flood impacts.
Source
World Weather Attribution (2025). Climate change intensified heavy monsoon rain in Pakistan, exacerbating urban floods that impacted highly exposed communities.