Adaptive urban economies: evidence of intra-day temporal behavioural adaptation to extreme heat in Australian cities

As cities confront the intensifying impacts of climate change, understanding human adaptive behaviour becomes increasingly important for urban resilience planning. This study provides the first empirical evidence of intra-day temporal behavioural adaptation to extreme heat across Australian cities. Using anonymised, large-scale bank card transaction data and daily temperature records in Melbourne, Sydney, and Adelaide, we provide evidence that extreme heat events (≥35 °C) drive substantial time-of-day shifts in consumer spending behaviour. Specifically, we find that daytime spending collapses (particularly between 12 p.m. and 6 p.m.) while night-time spending is more resilient and even increases before and after extreme heat days. This adaptive response unfolds in three phases–anticipation, suppression, and recovery–underscoring the role of time, not just space, in urban climate adaptation. This work shows that the night-time economy constitutes essential behavioural infrastructure for climate adaptation, warranting greater attention in the design of heat-resilient cities.