Muhammad Adnan, Firdos Khan, Muhammad Abbas, Fahad Shahzad, TianXiang Yue
Extreme precipitation events are intensifying under climate change, driving escalating flood risks in some of the world’s most vulnerable regions. Pakistan is one of the most hydrologically diverse and flood-prone country, previous studies have largely emphasized seasonal or mean rainfall, leaving monthly maximum daily precipitation extremes (Rx1day at monthly resolution) underexplored, despite their direct role in triggering flash floods, landslides, and infrastructure failures. This study fills that gap by analyzing bias-corrected CMIP6 multi-model ensembles to project Rx1day-month precipitation extremes for SSP2-4.5 and SSP5-8.5 across seven hydroclimatic zones. Projections are assessed for the near future (2017–2044), mid-century (2045–2072), and late century (2073–2100), relative to the 1985–2014 baseline. Findings reveal strong spatial heterogeneity. Northern and northwestern highlands exhibit the largest absolute increases, with late-century monsoon monthly maxima of daily precipitation reaching approximately 130–150 mm, nearly double baseline values. Central and southern zones also experience pronounced amplification, intensifying flash-flood, riverine, and urban drainage hazards. By contrast, western arid and coastal regions show a decline in the magnitude of monthly maximum daily precipitation, punctuated by occasional high-intensity events. Intensification is most under SSP5-8.5, where both the magnitude and spatial footprint of extremes expand significantly over time. These high-resolution, zone-specific projections demonstrate that even localized shifts in extreme rainfall can compound hazard exposure, destabilize agriculture, and overwhelm water-management systems. The results provide actionable evidence for strengthening early-warning capacity, guiding resilient infrastructure planning, and informing targeted adaptation in one of the world’s most flood-exposed countries.