Abstract
In the United States, severe weather events increasingly drive power outages, likely with health consequences. Studies typically examined individual severe weather events (e.g., heatwaves), focused on large power outages, and considered small geographic areas (e.g., a city). Here, we described the geographic and temporal patterns of all 8+ hour outages co-occurring with individual (e.g., cyclone alone) and multiple simultaneous severe weather events (e.g., cyclone + anomalous heat) nationally. We used hourly county-level PowerOutage.us data from 2018–2020 to define 8+ hour outages as whenever the proportion of customers without power was ≥0.1% for ≥8 continuous hours. We identified county-level daily severe weather events, including anomalous cold, anomalous heat, tropical cyclones, anomalous precipitation, wildfire, and snowfall. Of 1,657 counties with reliable power outage data, 1,229 (74.2%) experienced an 8+ hour power outage co-occurring with an individual severe weather event, and 880 (53.1%) faced co-occurrence with multiple simultaneous severe weather events. Outages co-occurring with anomalous precipitation events were the most common, affecting 1,158 (69.9%) counties, and concentrated along the Gulf Coast, Northeast, Michigan, and counties with data in Southern California. Co-occurrence with anomalous heat occurred the second most frequently, affecting 742 (44.8%) counties, mostly in Southeastern states. Cyclones – though rarer – affected the Eastern Seaboard and co-occurred with an 8+ hour power 24% of the time. On the West Coast, outages co-occurring with wildfires became increasingly common. Among multiple simultaneous weather events, 8+ hour power outages co-occurred with simultaneous anomalous precipitation-anomalous heat on 1,003 county-days in 39 states, anomalous precipitation-cyclone on 695 county-days in 24 states, and anomalous cold-snowfall on 252 county-days in 27 states. Understanding the spatiotemporal distribution of co-occurring weather-outages can guide efforts to strengthen and weatherize the electricity grid, prepare communities for multi-hazard events, and allocate resources for resilience and recovery.