When the city heats up: mapping urban heat risks through environmental and socioeconomic factors in Quezon City, Philippines

Abstract While urbanization drives economic growth and development, it also intensifies urban heat, worsened by climate change and urban heat island effects, which continue to threaten public health, livability, and urban resilience in cities. This study develops and maps a localized heat risk index (HRI) for Quezon City, Philippines, integrating environmental exposure and socioeconomic vulnerability variables through a weighted framework derived using analytic hierarchy process based on expert input. Spatial analysis revealed that 81% of barangays, accounting for 70% of the city’s population, fall under high-risk HRI classification (0.61–0.80), with the highest mean HRI recorded in Barangay Manresa (0.731). High-risk areas are concentrated in the southern and southwestern zones of the city, characterized by dense urbanization, limited vegetation, and high surface temperatures. Intraurban heat islets, covering 31% of the study area, strongly overlap with high-risk HRI barangays, emphasizing the compounded effects of environmental and socioeconomic factors on heat risk. The study provides insights to complement the Quezon City Enhanced Local Climate Change Action Plan 2021–2050 by identifying priority areas for implementing nature-based solutions, such as expanding green corridors and enhancing urban biodiversity. These findings highlight the critical role of integrating vegetation, reflective surfaces, and reduced built-up densities in mitigating heat risks and improving urban resilience. The HRI framework offers a replicable model for assessing urban heat risks, supporting evidence-based policymaking, and enhancing adaptive capacity in other rapidly urbanizing cities.