Abstract Extreme flooding in Rio Grande do Sul has intensified concern about how climate change is influencing hydroclimatic hazards and reinforcing unequal impacts across urban systems. This study evaluates observed changes in temperature and precipitation extremes across the state and examines the May 2024 floods as a case study of evolving risk conditions in southern Brazil. The results indicate regionally consistent warming, increasing intensity of precipitation extremes, and amplified rainfall variability across multiple subregions. In this context, the 2024 floods are consistent with a higher probability of high-impact events under a warmer climate. In Porto Alegre, the most affected areas coincide with sectors where elevated surface-water presence intersects with high population density and infrastructural fragility, demonstrating a clear spatial overlap between environmental exposure and socioeconomic vulnerability. The event also underscores the linkage between climate extremes and public health, as flood-related disruptions to essential services increased health risks in densely inhabited areas. Overall, these findings indicate that the 2024 floods align with broader regional climatic trends and highlight the need for risk-informed urban planning, infrastructure adaptation, and climate-responsive public health strategies in regions facing intensifying hydroclimatic extremes.
Terassi et al. (Fri,) studied this question.