Development and Evaluation of a Health-Based Heat Wave Categorization System: A Case Study of Seville, Spain

In the summer of 2022, a team of climatologists and researchers piloted the first heat warning system that ranks heat events based upon human health outcomes. This system uses local all-cause mortality data in addition to meteorological factors including air mass identification and the Excess Heat Factor to identify heat events that are likely to endanger human health in the region and applies three categories representing increasing severity. In this study, the authors evaluated this system by comparing the heat events it identified in Seville, Spain, between 1995 and 2022 with those identified by the Spanish national meteorology agency (AEMET). They found that the system captured more dangerous heat events than the meteorology-only criteria of AEMET and that the majority of identified heat events occurred during periods of elevated mortality. Overall, the results show the potential of health-based warning systems in identifying dangerous events that might be missed by traditional meteorology-based systems.