Heatwave adaptation conditioned by everyday life: Analysing interacting changes to daily activities during Pacific Northwest summers

As heatwaves increase in intensity, frequency, and duration, there is an urgent need for adaptation to limit their adverse effects on health, well-being, and livelihoods. Heat exposure and adaptive responses during heatwaves are tightly linked to mobility behaviours – the subject of a rapidly growing body of literature. However, knowledge of the processes which shape and constrain opportunities to seek cooling remains limited, as academic research has yet to examine how people alter the various activities of everyday life in response to heatwaves. Addressing this gap, the current paper models these interdependent activity changes simultaneously, shedding light on behavioural adaptations during heatwaves and the underlying structures which condition them. Combining Google Community Mobility Reports, ERA5 climate re-analysis, and socio-economic data across the Pacific Northwest region of North America, the analysis uses a multi-variate multi-level model to examine how anchor (home, work, transit), essential (grocery/pharmacy), and discretionary (retail/recreation, parks) activity change together during summer heatwaves. Focusing on a climatically diverse region and modelling heatwaves as distinct multi-day events, these interdependent responses are explored with the climatic, temporal, and contextual features of heatwaves. Four main conclusions about behavioural adaptation to heatwaves are drawn: (1) A region’s typical climate impacts workplace rigidity and adaptations to non-work activities during heatwaves; (2) Absolute and relative intensities have distinct yet comparably large impacts on behavioural responses; (3) Adaptation evolves over time, both between and within heatwaves; (4) Urban form and socio-economic disparities influence activity trade-offs during heatwaves. By contextualizing heatwaves within people’s everyday lives, this study highlights the diverse, dynamic, and yet constrained processes by which adaptation occurs.