Precipitation Extremes in the Argentine Pampas: Current Declining Trends and Projected Intensification Under Climate Change

Climate change is intensifying precipitation extremes globally, posing challenges to agriculture and water management in vulnerable regions such as the Argentine Pampas, one of the world’s major agricultural zones. This study analyses long-term evolution of precipitation patterns and extremes in the Argentine Pampas to inform agricultural planning, water management and adaptation strategies. We examine spatiotemporal variability across three time periods: present (2010–2024), near future (2025–2039) and far future (2085–2099). Ten precipitation indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI) were assessed using data from 48 meteorological stations and projections from two global climate models (CCSM4 and CNRM-CM5) under RCP 4.5 and RCP 8.5 scenarios. Currently, several indices show significant decreasing trends, especially annual precipitation on wet days (Prcptot), where 71% of stations showed statistically significant trends (Mann–Kendall test, p < 0.05), maximum 1-day precipitation (RX1day) at 53% of decreasing stations, and consecutive wet days (CWD) at 73%. However, under the RCP 8.5 far-future scenario, rainfall extremes intensify substantially. Prcptot increases in 65% of stations (+160 mm/15 years), extremely wet days (R99p) increase in 88% of stations (+96 mm/15 years), and heavy precipitation days show marked increases in northern and eastern areas. The northeast emerges as the most vulnerable subregion, while southern and western areas show more moderate increases. These findings inform targeted adaptation strategies for managing future precipitation variability.