Quantifying Event-Based Heatwave-Induced Power Outage Risk: A Multi-Year Spatiotemporal Analysis in Texas

Heatwaves are intensifying across the southern United States, particularly in Texas, placing unprecedented stress on electric distribution networks and increasing power outage risk. Yet the relationship between heatwave characteristics and observed outages remains poorly quantified at multi-year, statewide scales. This study develops an event-based, spatiotemporal framework to quantify heatwave-induced outage risk across 254 Texas counties from 2014–2021 by integrating county-level EAGLE-I outage records with reanalysis-derived heat index measurements. An adaptive percentile-based threshold identifies heatwave days and constructs multi-day events, from which event-level metrics duration, mean heat index, and maximum customers affected are derived. Across 3,048 identified heatwave events, 51% involved at least one outage, revealing widespread heat-related reliability challenges. Spatial indicators show substantial heterogeneity: some counties experience frequent minor outages, while major population exposure is concentrated in large urban load centers. Outage severity and duration exhibit heavy-tailed distributions, with a small number of extreme events disproportionately affecting customers. Logistic regression models under three severity definitions (P90, P95, and ≥500 customers) demonstrate that heat intensity is a significant probabilistic driver of major outages, with each +1 °F increase in mean event heat index raising the odds by approximately 43–52%. These findings offer a scalable methodology for climate-related reliability assessment, supporting grid hardening, resource planning, and public-health preparedness.