Geo-hydrological hazards, including floods and landslides, are among the most widespread hazards and a major cause of human loss worldwide. Their impacts are shaped by meteorological forcing and by long-term changes in exposure, vulnerability, and settlement patterns. Yet robust assessments of long-term fatality trends are rare because sufficiently long, accurate, and homogeneous records of damaging events are lacking. A key unresolved question is whether the human toll of geo-hydrological events has changed structurally through time, and which climatic, socio-economic, or policy factors best explain that change. Here we show, using a unique 1950–2024 catalogue of fatal events in Italy, that geo-hydrological risk underwent a marked transition, with fatalities and fatal days declining sharply until about 1970 and then stabilising at much lower levels. This decline was driven mainly by landslides, whereas flood-related losses showed weaker long-term change. The decline was not explained by specific risk policies or management programmes, as most of it preceded their implementation. Instead, precipitation was the main climatic driver of the remaining interannual variability, particularly for floods and days with fatal events. By contrast, population and gross domestic product did not account for the long-term trends once shared temporal changes were considered. Fatal days were less overdispersed and more predictable than fatalities, suggesting that meteorological factors control more directly the occurrence of dangerous conditions than the final death toll. Fatalities, instead, depend strongly on exposure, vulnerability, timing, location, and other event-specific circumstances. Together, these findings indicate that broad socio-economic dynamics can reduce geo-hydrological mortality even as hazardous processes persist, whereas meteo-climatic conditions continue to shape year-to-year risk.