As cities grow, they tend to become significantly warmer than their surrounding areas—a phenomenon known as the Urban Heat Island (UHI) effect. This increased heat not only affects human comfort and health but also raises energy demands, especially in densely built environments. This study investigates how natural elements within cities—such as vegetation, moisture, and green spaces—can help reduce surface temperatures and contribute to urban thermal sustainability. Focusing on Tehran, we analyzed satellite imagery from 2024 to assess how different environmental indicators relate to surface temperature across the city’s 22 municipal districts. We used a statistical method called the Band Collection Statistics (BCS) algorithm to examine correlations between land surface temperature and several environmental variables. Among them, four key indicators—vegetation density (NDVI), vegetation moisture (NDMI), surface water presence (NDWI), and urban park density—showed significant relationships with temperature. Results indicate that areas with more water and higher moisture content tend to be cooler than those with vegetation alone. This suggests that water availability and moisture retention may play a more critical role in reducing urban heat than the mere presence of greenery. These findings highlight the importance of integrated blue-green infrastructure strategies that not only increase vegetation but also focus on preserving moisture. The study offers insights for urban planners and policymakers aiming to develop context-specific cooling strategies to enhance livability and environmental resilience in rapidly growing cities like Tehran.