Urban form and park cooling performance during extreme heat events: a case study in melbourne

Urban parks are vital for mitigating urban heat stress, yet their cooling effectiveness is strongly shaped by their surrounding urban forms. This study applies the Local Climate Zone (LCZ) framework to evaluate park cooling performance across three residential urban contexts in Melbourne. Field-validated ENVI-met simulations were used to examine diurnal and nocturnal patterns in air temperature (AT), mean radiant temperature (MRT), and physiological equivalent temperature (PET) during an extreme heat day. The results revealed pronounced diurnal and nocturnal differences in park performance across urban forms. During the daytime, the park embedded in LCZ1 showed the strongest thermal mitigation, with reductions of up to 12 °C in MRT and 8 °C in PET relative to the low-rise settings, primarily associated with extensive shading from surrounding buildings. At night, this advantage reversed, as LCZ1 exhibited weaker cooling performance due to greater heat storage, restricted sky exposure, and reduced ventilation. In contrast, LCZ3 and particularly LCZ6 demonstrated stronger nocturnal cooling, with cooling spillover in LCZ6 extending up to 150 m beyond the park boundary. Across selected LCZs, daytime thermal conditions were most strongly associated with land surface temperature (LST), while nighttime cooling patterns were more sensitive to wind speed and sky exposure. The relative importance of view factors differed by context. Building view factor (BVF) was more influential in LCZ1, whereas sky view factor (SVF) and vegetation view factor (VVF) played larger roles in LCZ3 and LCZ6. These findings indicate that park design and placement should be tailored to surrounding urban morphology. Context-based design strategies can support better cooling impact of urban parks and can help urban planners and policymakers in implementing sustainable park design strategies that maximize cooling benefits, improve outdoor thermal comfort, promote healthier urban environments, and contribute to more heat-resilient and climate-adapted cities.