The most sweltering “hot spots” in the urban centers of Los Angeles and New York have been revealed in Urban Heat Snapshot, a new survey of six cities by global sustainable development consultancy, Arup.
Cities are getting hotter due to climate change, with the number of urban areas exposed to extreme temperatures, 95°F and above, expected to triple by 2050. As global temperatures rise, this survey focuses on how design can influence the urban heat of cities. In combination with the changing climate, the urban heat island (UHI) effect is contributing to dramatically increased urban temperatures. The effect is caused by a lack of natural land cover in cities, where pavement, buildings, and other heat absorbing materials absorb and re-emit heat, causing higher temperatures to be sustained in urban areas as compared to their surrounding areas.
Using artificial intelligence (AI) and satellite images from space, Arup’s Urban Heat Snapshot mapped the temperatures within a 58mi² sample of the urban centers of a diverse range of cities: Cairo, London, Los Angeles, Madrid, Mumbai, and New York. Drawing from rapid analysis conducted using Arup’s in-house digital analytics tool UHeat, the survey reports the urban air temperatures experienced during the hottest days of 2022.
The snapshot is designed to help cities understand how heat is impacting them both between the urban settings and their periphery as well as from one neighborhood to another. This new survey is also one of the few international comparisons of the UHI effect on air temperatures during both day and night-time, which more accurately reflects people’s experience. To continue applying UHeat and the survey findings to real-world scenarios, Arup is keeping in mind the importance of combining digital tools with local factors and knowledge to inform mitigation strategies. Prioritizing the deployment of nature-based solutions can help cities equitably reduce the impact of the UHI effect.