Exploring the impact of urban features on land surface temperature over South Asian cities

Extensive research has established that urban land cover plays a critical role in modulating land surface temperature (LST), with urban morphology and surface heterogeneity driving its spatial and temporal variations. Studies have also highlighted that the increasing frequency, intensity, and duration of extreme heat events exacerbate urban thermal stress, significantly impacting livability and thermal comfort. This study utilizes high-resolution (70 m) LST data from NASA’s Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) to investigate the diurnal cycling of LST and its variations across local climate zones (LCZs) in two major South Asian cities, Delhi and Lahore. ECOSTRESS LST images from four distinct heatwave events (2020–2023) were analyzed to quantify intra-LCZ variations and surface urban heat island (SUHI) intensity at different times of the day and night. Results indicate significant diurnal thermal disparities among LCZs, with the highest average SUHI observed in Lahore (3.48°C), while Delhi also exhibited a positive SUHI effect (0.46°C). Findings revealed distinct spatial LST patterns across LCZs, highlighting the role of urban vegetation and impervious surfaces in regulating SUHI intensity. Additionally, urban heat hotspots and coldspots were identified, largely influenced by the characteristics of the underlying LCZ types. The study provides critical insights into the spatiotemporal dynamics of SUHI during extreme heat events, offering a valuable reference for urban planners and policymakers in designing climate-resilient cities and mitigating urban heat stress.