Seasonal Variations of the Relationship between Spectral Indexes and Land Surface Temperature Based on Local Climate Zones: A Study in Three Yangtze River Megacities

Urban heat islands are representative problems in urban environments. The impact of spectral indexes on land-surface temperature (LST) under different forms, climates, and functions is not fully understood. Local climate zones (LCZs) used to characterize heterogeneous cities. In this study, we quantified the contribution three cities high-temperature surface island intensity (SUHII) across LCZs seasons, Welch Games–Howell tests analyze difference LST, then described spatial pattern characteristics a geographically weighted regression model relationship between LST. results showed that compact midrise, low-rise (LCZ 3), large 8), heavy industry 10), bare rock or paved E) contributed greatly had strong SUHII. There were 92–98% significant differences LCZs. aggregation LST gradually weakened with decrease temperature. modified normalized water index (MNDWI) most all seasons for Wuhan could reduce well, while MNDWI only cooling effects winter Nanjing Shanghai. Normalized vegetation (NDVI) performed role during summer transition (spring autumn), it warming effect winter. NDVI open building types was stronger than types, better types. With increase built-up (NDBI), effects, magnitude varied seasons. These contribute further insight into thermal environment areas.