Multi-level heat island monitoring in the Beijing-Tianjin-Hebei region during the summers of 2019-2024 using FY-3D LST data

Urban Heat Island is a significant urban climate phenomenon, particularly during extreme heat events, with profound impacts on environmental sustainability and human well-being. This study investigates UHI dynamics in the Beijing-Tianjin-Hebei (BTH) region during the summers of 2019–2024 using FY-3D satellite-derived Land Surface Temperature (LST) data. Employing Dynamic Equal-Area UrbanHeat Island Classification (DEA) combined with the Beijing local standards, UHI intensity was quantified and classified into five levels to analyze spatiotemporal variability and transitions across intensity levels. The results reveal a pronounced UHI intensification in 2023, with cities such as Beijing, Tianjin, and Rwanda exhibiting intensity values exceeding 2K. High-intensity UHI zones expanded significantly, particularly in southern Hebei, while 2022 and 2024 showed similar, lower-intensity patterns. These findings provide strong evidence supporting the occurrence of record-breaking localized temperatures in the BTH region during 2023. This study underscores the value of FY-3D data for precise UHI monitoring, offering robust quantitative assessments and spatial distribution insights. The findings lay a foundation for developing effective heat mitigation strategies and sustainable urban planning in rapidly urbanizing regions.