Compound drought-heat wave hazards are concentrated in US regions with multiple social vulnerabilities and...

Compound drought and heat wave (CDHW) events are becoming more frequent and intense across the contiguous United States, increasing risks to human health, ecosystems, agriculture, and energy production systems. However, their distribution across socioeconomically vulnerable communities remains largely unexplored at the national scale. In this study, we develop a CDHW metric by integrating weekly US Drought Monitor classifications with daily temperature extremes from 2000-2021, allowing consistent mapping of CDHW occurrences along county-level socioeconomic conditions. Our analysis reveals significant regional differences, with elevated CDHW occurrences concentrated in the South, Southeast, and western United States. Regions facing greater socioeconomic challenges, including poverty, high agricultural employment, and health-related vulnerabilities, experience notably higher CDHW risks. Greater spatial concentration of CDHW occurrences, as indicated by higher Gini coefficient values, occurs where multiple socioeconomic vulnerabilities intersect, such as in counties with large poor populations and older housing. These findings indicate that CDHW events are unevenly distributed across socially vulnerable communities, underscoring the need for targeted adaptation strategies to reduce climate risks for the most vulnerable communities.