Historical changes in the seasonality and timing of extreme precipitation events

Global warming alters the hydrological cycle, influencing the seasonality and timing of extreme precipitation events. Understanding historical changes in the occurrence of extreme precipitation is important for assessing their effects. This study examines the timing and seasonality of extreme precipitation using 63 years of ERA5 data. By using relative entropy, we can assess changes in extreme daily precipitation occurrence on the global domain. Findings show notable regional differences. In the second half of the 20th century, Africa and Asia had high clustering of extreme precipitation events. Over 60 years, clustering intensified in Africa but became more spread out in Asia. North America and Australia, initially with less clustering, saw slight increases. Extreme precipitation events in extra-tropical land regions mainly occurred in summer, with minor shifts in timing. These results are important for improving risk management for hazards like flash floods and landslides and highlight the need for region-specific strategies in adapting to these changes.