The Weather Extremes Archive (WEXA)

Abstract. The Weather Extremes Archive (WEXA) is a global, event-based dataset designed to systematically detect, track, and document persistent weather extremes. In its initial release, WEXA focuses on heat waves and cold spells identified from 2-m air temperature in ERA5 reanalysis data from 1979 to present. Cold and warm extremes are defined using seasonally varying 10th and 90th percentile thresholds derived from a fixed 1991–2020 climatological baseline. Periods of at least three consecutive extreme days are grouped into coherent spatiotemporal heat waves or cold spell events using three-dimensional connected component labelling. WEXA delivers a global catalogue of all detected individual heat wave and cold spell events, providing standardized diagnostics of their timing, duration, spatial extent, and intensity. The archive is openly accessible at https://doi.org/10.5281/zenodo.20550615 and https://wexa.jamstec.go.jp, permitting the exploration of event statistics and visualizations through an interactive analysis tool.