A Local Climate Zone-Based Seasonal Net-Benefit Assessment Model for the Urban Thermal Environment—A Case Study in a Cold-Region City

The combined effects of urbanization and climate warming subject cold coastal cities to summer heatwaves and winter extreme cold, yet most studies emphasize built-environment modifications for summer overheating and lack evaluation methods and planning-oriented strategies to balance seasonal trade-offs. Using Dalian as a case study, we develop a seasonal net-benefit model that quantitatively characterizes and reconciles seasonally differentiated built-environment effects on land surface temperature (LST) and interprets urban heterogeneity within the Local Climate Zone (LCZ) framework. Summer LST is mainly governed by static factors such as greenspace configuration and topography, whereas winter LST is more sensitive to development intensity and locational factors, including building density and the Normalized Difference Built-up Index (NDBI). Coastal areas and mountainous green corridors are net-benefit zones performing well in both seasons, while dense industrial and compact low-rise areas account for ~80% of pronounced net-penalty zones. Compact mid- and high-rise neighborhoods show more favorable structural climatic conditions but with substantial retrofit potential (Retrofit Seasonal Net-Benefit Index (R-SNBI) markedly lower than Structural Seasonal Net-Benefit Index (S-SNBI) by ~3). Large low-rise problems mainly stem from an unfavorable structure rather than insufficient greenness, whereas industrial land has greater improvement potential via blue–green spaces. The framework supports refined climate adaptation, sustainability-oriented planning, and identifying urban renewal priority areas in cold-climate cities.