Characterising City Scale Heat Climatology for Australian Climate Zones

ABSTRACT

There is a critical need for high‐resolution climate models that accurately capture urban influences on local climates to improve climate risk assessments and support adaptation planning. However, current down‐scaled climate models used for urban heat risk quantification fail to represent urban–rural warming disparities, leading to severe underestimation of urban effects. This underestimation has significant ramifications, especially while considering climate adaptation solutions to manage urban heat impacts. To address this gap, this study uses a consistent quantification approach to evaluate the heat climatology across six Australian coastal capital cities in diverse climate zones at a city scale. Warmer urban conditions relative to rural areas drive the Urban Heat Island (UHI) effect, quantified by the UHI Intensity (UHII). The results reveal that UHII peaks at night, particularly in minimum temperatures (), with seasonal variations influenced by total cloud cover (TCC), solar radiation, precipitation and wind speed. Drier conditions, increased solar radiation and reduced TCC increase nighttime UHII, whereas precipitation and higher wind speeds reduce it, highlighting the effect of weather patterns on urban–rural temperature disparities. Long‐term observations (1960–2021) show that major cities, including Sydney, Melbourne, Adelaide, Perth and Brisbane, are warming faster than their rural counterparts, predominantly at night. Temperate cities like Melbourne can better accommodate population growth than humid tropical cities like Brisbane and Darwin, where UHI effects peak during drier months. This study highlights the need for improved urban representation in high‐resolution climate models, especially at a regional or city scale and the importance of tailoring urban heat adaptation strategies utilising the outcomes from such city‐scale urban impact assessments.