Warming leads to both earlier and later snowmelt floods over the past 70 years

• DOI: 10.1038/s41467-025-58832-0
• Publication Date: 2025-04-17T14:21:39Z
• Authors: Yuhan Guo; Yuting Yang; Dawen Yang; Lu Zhang; Hongxing Zheng; Jinghua Xiong; Fangzheng Ruan; Juntai Han; Ziwei Liu
• Keywords: Snowmelt

Climate warming reduces snow cover in cold regions, altering snowmelt flood regimes with significant hydrological and ecological consequences. Existing evidence indicates that as climate warms, tends to begin earlier the season, leading floods. Here we show timing of floods can be either advanced or delayed under warming. Using streamflow observations from 1950-2020 an event-based analysis distinguishes flood-generating mechanisms across 2339 Northern Hemisphere, snow-affected catchments, effect substantially offset even reversed by a decelerated rate This results approximately 30% contributing overall minor shift on hemispheric scale (-0.87 ± 2.4 days per decade). Our findings challenge prevailing "warming leads floods" paradigm, revealing more complex pattern changes world.