Understanding the morphology of cities

We are interested in how urban areas are structured, and the relationship between the built, natural and human environments. We extend a lengthy history of research at the University of Liverpool in the development and application of new area classification.

Extreme heat reduces and reshapes urban mobility

Extreme heat is a growing societal challenge in cities worldwide, aggravated by climate change. Yet we still lack systematic evidence about how populations adapt their everyday mobility during hot weather, or how these responses vary for different social groups.

Using mobile phone data covering 13 million people in Spain (27% of the population), we examine how extreme heat affects daily movement. We find that mobility drops by around 10% on hot days, and by up to 20% in the afternoon when temperatures peak. These effects are uneven across social groups: older adults tend to reduce travel to work and other activities more, whereas less affluent people do not change their usual mobility patterns as much.

Extreme heat also reduces mixing of different socioeconomic groups as activity declines in city centres. These findings show significant evidence that heat disrupts mobility, and suggests it may also amplify social inequalities and weaken the socioeconomic dynamism of cities.

Publication

Renninger, A., & Cabrera, C. (2026). Extreme heat reduces and reshapes urban mobility. PNAS Nexus (in press).