Historical Shifts in Seasonality and Timing of Extreme Precipitation.

Global warming impacts the hydrological cycle, affecting the seasonality and timing of extreme precipitation. Understanding historical changes in extreme precipitation occurrence is crucial for assessing their impacts. This study uses relative entropy to analyze historical changes in seasonality and timing of extreme daily precipitation occurrences on the global domain for 63 years of fifth generation of the European Reanalysis reanalysis data. Our analysis reveals distinct regional patterns of change. During the second half of the 20th century, Africa and Asia experienced high clustering of precipitation extremes. Over the past 60 years, clustering increased in Africa while becoming more spread out in Asia. North America and Australia had initially lower clustering and showed slight increases over time. Extreme events in extra‐tropical land regions mainly occurred in summer, with modest shifts in timing. These findings have implications for risk assessments of natural hazard like flash floods and landslides, emphasizing the necessity for region‐specific adaptation strategies. Plain Language Summary: Global warming is changing how and when heavy rain and extreme weather events happen. It is important to understand these changes for planning and preparing for floods and other water‐related problems. In this study, we looked at long records of rainstorms to see how they have changed over time. We found that different regions have experienced different changes. During the second half of the 20th century, Africa and Asia were regions with the strongest seasonality. Over the 60 years we analyzed, seasonal clustering overall increased in Africa, while in Asia they became more spread out throughout the year. In Europe, North America and Australia, rainstorms were more spread out throughout the year but became slightly more concentrated. Most of the heavy rainstorms outside the tropics happened in summer, with a small shift in timing. These findings show how various regions have experienced different changes, which is important to take into account when planning and preparing for floods. Key Points: Global assessment of changes (1959–2021) in seasonality and timing of extreme daily precipitation occurrences using relative entropyPrecipitation extremes became more clustered in Africa and less clustered in AsiaShifts in timing of extreme precipitation by only a few days for most regions [ABSTRACT FROM AUTHOR]