Article
Unpacking Park Cool Island Effects Using Remote-Sensed, Measured and Modelled Microclimatic Data Bill Grace, Julian Bolleter * , Maassoumeh Barghchi
and James Lund
Australian Urban Design Research Centre, School of Design, University of Western Australia, Perth, WA 6009, Australia; bill.grace@uwa.edu.au (B.G.); maassoumeh.barghchi@uwa.edu.au (M.B.); james.lund@uwa.edu.au (J.L.) * Correspondence: julian.bolleter@uwa.edu.au
Abstract
Academic Editor: Julia Nerantzia Tzortzi Received: 4 July 2025 Revised: 4 August 2025 Accepted: 12 August 2025
There is increasing interest in the role of parks as potential cool refuges in the age of climate change. Such potential refuges result from the Park Cool Island (PCI) effect, reflecting the temperature differential between the park and surrounding urban areas. However, this study of different park typologies in Perth, Australia, illustrates that while surface temperatures are 10–15 ◦ C lower in parks during summer afternoons (much less than at other times), air temperatures are generally no different from the adjacent streetscape for the smaller parks. Only the largest park in the study had 1–2 ◦ C lower morning and mid-afternoon air temperature differentials. The study illustrates that while the PCI is a real phenomenon, the magnitude in terms of air temperature is small, and it is of less relevance to the conditions felt by humans in average summer daytime conditions than the direct effects of solar radiation. Many studies have assessed the PCI effect, an indicator that has shown a wide range across different studies and measurement techniques. However, this novel paper utilises satellite remote-sensed land surface temperatures, onground measurements of surface temperatures, air temperatures, and humidity, as well as modelling using the microclimatic simulation software ENVI-met version 5.0. A reliance on land surface temperature, which in isolation has a marginal correlation with human experience of thermal comfort, has led some researchers to overstate the PCI effect and its influence on adjoining urban areas. The research reported in this paper illustrates that it is the shade provided by the canopy in parks, rather than parks themselves, that provides meaningful thermal comfort benefits. Accordingly, adaptation to increasing temperatures requires the creation of a continuous canopy, ideally over parks, streetscapes, and private lots in an interconnected network.
Published: 20 August 2025 Citation: Grace, B.; Bolleter, J.; Barghchi, M.; Lund, J. Unpacking Park Cool Island Effects Using
Keywords: park cool island effect; urban heat island effect; public open space; climate adaptation; climate sensitive urban design
Remote-Sensed, Measured and Modelled Microclimatic Data. Land 2025, 14, 1686. https://doi.org/ 10.3390/land14081686 Copyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/ licenses/by/4.0/).
Land 2025, 14, 1686
1. Introduction Many parts of Australia already have extensive exposure to extreme summer conditions. Perth (the capital city of Western Australia and the focus of this paper) has summer days that often exceed 40 ◦ C, which is projected to worsen with climate change. Recent updates on global warming [1] project that, with current real-world policies and actions (as opposed to national pledges and targets), global temperature increases of 2.2–3.4 ◦ C above pre-industrial levels are likely by the end of the century and will continue to rise thereafter. These conditions will have dire implications for Australian cities, particularly for
https://doi.org/10.3390/land14081686