Assessing the spatiotemporal cooling performance of urban parks under extreme and non-extreme heat conditions: a case study in Melbourne

Purpose This study aims to provide a direct microscale comparison of urban park cooling dynamics under extreme and non-extreme summer heat conditions. It evaluates the cooling performance of a neighborhood park in Melbourne, Australia, and examines how extreme heat influences the intensity and spatial distribution of its diurnal and nocturnal cooling effects. Design/methodology/approach Air temperature (AT) and relative humidity (RH) were measured at Central Gardens, a neighborhood park in Hawthorn, Melbourne, during the summer of 2025 under extreme and non-extreme conditions. Park cool island (PCI) intensity was calculated from the temperature difference between park monitoring points and an urban reference site. ENVI-met was validated against field observations for representative extreme and non-extreme days, producing AT R2 values of 0.960 and 0.869, respectively. The validated model was then used to examine the spatial distribution of AT and PCI across the park and its surrounding urban area. Findings Under non-extreme conditions, peak PCI reached 2.95°C around midday. During the heatwave, cooling was stronger at night, reaching 3.49°C around midnight, particularly beneath tree canopies. However, mean nocturnal PCI declined from 1.04°C on 8 March 2025 to 0.52°C by 12 March 2025 as the heatwave progressed. ENVI-met simulations indicated that tree-covered areas maintained lower AT and stronger PCI, while exposed turfgrass, playgrounds, and impervious surfaces experienced greater warming and weaker or negative PCI during the late afternoon. Originality/value This study provides microscale comparisons of urban park cooling performance under both extreme and non-extreme summer heat conditions by integrating continuous field measurements with validated ENVI-met simulations. Unlike previous studies that have typically examined either normal summer conditions or extreme heat in isolation, this research demonstrates how extreme heat alters not only the magnitude but also the temporal and spatial distribution of park cooling. The findings provide practical evidence to support climate-responsive park design and heat adaptation strategies in Melbourne and other temperate cities.