Decoding the urban heatscape: Suburb-level analysis of long-term extreme heat hazard in Brisbane

Extreme heat poses a growing threat to Australian cities, yet traditional assessments often overlook its local variability. This study analyses suburb-level heat hazard associated with extreme heat events in Brisbane using over five decades (1971–2024) of daily temperature data from 47 weather stations. Instead of satellite proxies or demographic models, it applies Australia's Bureau of Meteorology Extreme Temperature Indices (ETIs) to capture actual daytime and nighttime thermal conditions. Seven ETIs were assessed using a triangulated approach combining Mann-Kendall trend analysis, Z -score anomaly detection, and Getis-Ord Gi* spatial clustering. Results were synthesised into a Heat Hazard Index (HHI) and spatially interpolated across 190 suburbs. Findings reveal a distinct east–west and day–night divide: nighttime heat is more spatially widespread, especially in dense eastern and central areas, while daytime extremes are concentrated inland and west. Overall, 188 suburbs exhibit elevated heat hazard across at least one form of ETI, with 109 experiencing high heat hazard across both daytime and nighttime conditions. These findings highlight the limitations of city-wide averages and emphasise the importance of spatially targeted climate adaptation strategies. The framework, developed for the Australian context with long-term observational datasets such as the Scientific Information for Land Owners (SILO) climate database, offers a scalable approach for assessing urban heat hazard in cities with comparable monitoring networks. By translating empirical climate observations into suburb-scale insights, the study contributes to data-driven and equitable urban climate planning aligned with global sustainability frameworks including the UN Sustainable Development Goals and the New Urban Agenda.