<p>The pathogenic causes and social determinants of death have been extensively explored; however, the role of environmental factors in shaping mortality disparities remains underexamined. By linking mortality with climate data and sociodemographic information from 2009 through 2019, we explored the impacts of temperature, air quality, and their interactions on cause- and age-specific mortality at the county level in the United States over the past decade. We found an environment-induced rural paradox and urban penalty, alongside the well-documented rural mortality penalty. Specifically, as temperatures and PM_2.5 levels increased, rural areas faced a cardiovascular mortality penalty among infants, while a rural paradox in respiratory mortality emerged, with lower respiratory mortality observed in rural areas. Additionally, we observed an urban respiratory mortality penalty among working-age adults under increasing temperatures and worsening air pollution conditions. The findings emphasized the critical role of environmental conditions in shaping health disparities and underscored the importance of targeted public health interventions.</p>