At the same time, some activity shifts into cooler periods. Dining, entertainment and retail spending partially recover during the evening and in the days following heat events. Grocery shopping and essential trips move earlier into the day, while several sectors begin to display spending patterns that increasingly extend across a dawn, twilight and night-time economy rather than a traditional daytime one.
The behavioural effects of heat are concentrated less in whether activity occurs than in when it occurs. Spending and movement fall sharply during the afternoon heat window, roughly between 12pm and 6pm, while the cooler periods at either end of the day remain comparatively resilient. Exercise, commuting, grocery shopping and essential trips may move earlier, while dining, entertainment and social activity shift later. Overall, Australian cities are beginning to develop a broader cooler-hours economy, encompassing dawn, twilight and night.
These behavioural shifts matter because many urban systems are still heavily geared towards conventional daytime demand. Public transport may begin too late to support early-morning activity and often reduces in frequency after 7pm. Community facilities operate within fixed business hours. Public spaces may lack lighting, amenities or passive surveillance during the early morning and after dark. Yet these are precisely the periods becoming more important during extreme heat events.
DAWN AND TWILIGHT BECOME PRIME TIME For years, infrastructure supporting activity outside conventional business hours has often been treated as secondary to the“ real” economy of daytime activity. Lighting, early and late public transport, public space management and extended operating hours have commonly been associated with tourism, hospitality, recreation or entertainment precincts. In many councils, these investments still sit within activation or events budgets rather than mainstream infrastructure planning.
Heat changes the equation. As temperatures rise, both the early morning and evening are becoming more important for basic economic and social participation. The dawn economy and the evening city are no longer simply about lifestyle, recreation or nightlife. They are increasingly part of how households adapt to climate stress.
This has practical implications for local government. Cities that function well across the cooler hours may become more economically resilient during heat events. Public transport that begins early and remains frequent into the evening allows households to bring trips forward or delay them until temperatures ease. Safe walking and cycling routes, accessible public toilets, well-lit parks and waterfronts, and libraries, aquatic centres and community hubs with extended summer hours support activity at both ends of the day. These are relatively modest interventions compared with largescale infrastructure retrofits, yet they can materially reduce disruption by allowing activity to shift into more tolerable periods.
TOWARDS THE CLIMATE- RESPONSIVE 24-HOUR CITY Australian cities are not the first to organise economic and social life around the cooler hours of the day. In parts of Southern Europe, Asia, Latin America and the Middle East, everyday routines have long adapted to heat through combinations of early-morning activity, midday retreat and later evening public life. Australian cities historically evolved around milder daytime conditions and stronger distinctions between daytime and evening economies. Those distinctions are becoming less clear during increasingly hot summers.
The data shows that the economic effects of heat are heavily concentrated in the afternoon. Spending declines sharply between 12pm and 6pm, while the cooler bookends of the day( the dawn economy, as well as twilight and evening activity) remain comparatively stable.
ECONOMIC DEVELOPMENT JOURNAL VOL 19 NO 2 2026 09