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Abstract Thunder hours represent both a historic measure of lightning occurrence and a metric of thunderstorm frequency that is comparatively less sensitive to variations in the detection capabilities of a lightning location system. The World Wide Lightning Location Network (WWLLN) has monitored global lightning since late 2004, and this paper introduces a WWLLN thunder hour climatology for 2013-2024, when the number of global sensors remained largely consistent. WWLLN reports nearly half as many thunder hours as the Geostationary Lightning Mappers (GLMs) even though its detection efficiency for all flashes is much lower, and the geographic distribution of thunder hours is similar to other global ground-based networks. WWLLN thunder hours are also compared with convective precipitation hours derived from the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM) dataset (IMERG). Various applications of thunder hours are explored, including variations related to diurnal, seasonal, and interannual cycles (the El Niño-Southern Oscillation, or ENSO). Brief case studies illustrate a variety of factors affecting thunderstorm occurrence and timing, including coastlines, terrain, and island size in the geographically complex Philippines. Thunder hour persistence provides a metric for understanding event duration, including geographic regions where the most frequent and most sustained thunderstorm hazards occur at different times of year. Comparisons with monthly European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5) fields quantify the relationship between thunder hours and measures of regional temperature, moisture, and instability.