Mapping Which Street Is Hottest, Block by Block

Urban heat is a street-level phenomenon: tree cover, building materials, road surface and airflow can put a ten-degree gap between neighbourhoods a few minutes apart, and adaptation money gets spent badly when it is allocated at city scale. WRI's Ross Center for Sustainable Cities launched Cool Cities Lab in March 2026, a free open-source platform funded by Google.org that maps heat risk down to individual blocks and streets using the Universal Thermal Climate Index — how heat actually feels to a person standing there, rather than air temperature alone. Crucially it also models interventions, so a city can compare what shade structures, tree planting or cool roofs would do on a specific street before committing. It covers more than 25 cities across five continents, and in Mexico is being used by Mexico City, Monterrey and Hermosillo — the latter two among the country's hottest, with Monterrey already running about 5°C warmer than the countryside around it.