Future Precipitation Trends Across Canadian Catchments: Insights from High-Resolution CMIP6 Downscaled Projections

Understanding how climate change affects precipitation patterns—spanning daily, seasonal, and extreme events—at the catchment scale is essential for assessing regional hydrological shifts and guiding water resource management. This study investigates future precipitation changes across eleven key Canadian catchments using 9-km downscaled simulations from CMIP6 under various Shared Socioeconomic Pathways (SSPs). Through detailed analysis of daily, seasonal, and extreme precipitation metrics, we reveal significant insights into future precipitation dynamics. The findings indicate substantial increases in daily precipitation, with northern and coastal regions showing the highest growth, particularly under the SSP5-8.5 scenario. Seasonal patterns reveal marked precipitation increases in spring and winter, with consistently elevated values in coastal and mountainous areas. Extreme precipitation events, including annual maxima and 95th and 99th percentiles, intensify notably under high-emission scenarios, with northern regions experiencing the most significant relative changes. These results emphasize the urgency of developing region-specific climate adaptation strategies to address emerging risks related to flooding, water resource management, and infrastructure resilience in the context of a changing climate.