Running barefoot from scorching asphalt to cool grass in the summertime as a kid, you likely learned how cityscapes tend to get much warmer than green spaces. Extreme heat can be fatal, and buildings and pavement increase its threat, making some parts of cities up to 20°F hotter than other parts.
This summer, citizen scientists will map these hot spots, known as “urban heat islands,” in 13 cities across the country to help communities identify areas where they can take action to protect people from heat stress.
The mapping campaigns are part of a collaborative project supported by NOAA’s Climate Program Office (CPO) and jointly coordinated by the National Integrated Heat Health Information System (NIHHIS) — a NOAA and Centers for Disease Control and Prevention effort — and CAPA Strategies LLC. They build on three years of past campaigns that have produced urban heat maps for 11 other U.S. cities.
“Our mapping campaigns engage residents in the scientific process, while teaching them about the Urban Heat Island effect — the extreme temperature difference between cities and surrounding rural areas — and ways to mitigate risk,” said Hunter Jones, Climate and Health Project Manager with NIHHIS and CPO. “They also produce data sets that are directly useful for managing heat exposure in cities to prevent heat-related suffering and death.”
During one of the hottest days of the year in each of the 13 cities, volunteers will drive prescribed routes in the morning, afternoon, and evening with custom-engineered heat sensors mounted on their own cars. Once per second, the sensors will record temperature and humidity, as well as the exact time and location along the route.
Using the data collected, the CAPA team will produce detailed urban heat maps for the 13 cities that will help city officials and community groups identify specific neighborhoods that are vulnerable to extreme heat. The cities can then determine whether and how to implement strategies like adding trees and green roofs, varying the height of new buildings to increase airflow and create shade canyons, and providing more access to public water parks and air-conditioned spaces.
Extreme heat kills over 600 Americans per year, but with such strategies these deaths are preventable. One study showed that implementing an urban heat island mitigation measure reduces the annual heat-related death rate by 15%.