Heat Resilience in Sight: Climate-Conditioned Thermal Affordance of Streetscapes Across Cities and Seasons

Trees, shade, and urban form of streetscapes can reduce heat exposure and enhance outdoor thermal comfort, which has been proposed as thermal affordance, but whether this thermal affordance $\mathit{supply}$ is sufficient depends on local climate $\mathit{demand}$ across cities and seasons. Street-view imagery (SVI) models map thermal affordance through visual cues at scale, yet their scores are difficult to compare across climates. We present Heat Resilience in Sight (HRIS), a framework that maps monthly climate demand from the Universal Thermal Climate Index (UTCI) onto a 0--5 street thermal-affordance scale using a Hong Kong summer reference. Its indicator, streetscape heat resilience (SHR), is supply minus required affordance. Across 892,466 SVIs in eight cities, thermal affordance supply alone places Melbourne with Singapore and Hong Kong among the highest-scoring cities, and Cape Town last. SHR instead puts Singapore near the adequacy boundary year-round. Rio's demand is lower than Singapore's, but its lower supply still leaves a substantial shortfall, especially in southern summer. Cooler cities remain in surplus despite more modest supply. Under $+1.5$/$+2.5\,^\circ$C warming, tropical shortfalls widen. Seasonal SHR maps help planners identify where vegetation, shade, and heat-health interventions warrant closer study.