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CPO and Community Scientists to Map Urban Heat Inequities in 11 States

Extreme heat kills more Americans than any other weather event, but not everyone’s risk is the same. Within the same city, some neighborhoods can be up to 20°F hotter than others and, due largely to the practice of historic redlining—discriminatory, race-based lending and housing policies in the 1930s— these hot spots are often home to poorer communities of color.

To learn where action is needed to protect vulnerable populations now and in the future, CPO’s National Integrated Heat Health Information System (NIHHIS) and partners are launching new community-led campaigns that will map the hottest parts of cities in 11 states across the country this summer. The communities include Albuquerque, New Mexico; Atlanta; New York City; Charleston, South Carolina; Kansas City, Missouri; Raleigh & Durham, North Carolina; San Diego; San Francisco; and parts of New Jersey, Indiana, Massachusetts, and Virginia. 

“Our Nation faces a growing climate crisis that has exacerbated inequities, particularly for the low-income and communities of color,” said U.S. Secretary of Commerce Gina M. Raimondo. “The Biden-Harris Administration is ready to take swift action to tackle climate change, and we at the Department of Commerce are so pleased to be partnering with communities around the country toward equitable climate resilience by working with them to design safer, more livable, and healthier cities.” 

The mapping campaigns are part of a collaborative project with CAPA Strategies, LLC and local partners that has empowered many other U.S. communities to map heat in their cities over the past four years. This summer’s new campaigns will cover neighborhoods on both coasts and across America’s heartland.

This map shows the locations of the 2021 urban heat island mapping campaigns cohort and previous campaign locations. NOAA is funding nine of the 2021 campaigns and partnering with four that have secured independent funding. The background shows the average window for the day of the year with the highest maximum temperature based on the 1981-2010 U.S. Climate Normals, the nation’s official record of recent climate. The colors show date ranges progressing from June 1 (lightest yellow) through September 30 (darkest red). The darker the color, the later in the year the hottest day typically arrives. Credit: using data from NOAA NCEI

Local maps for local solutions

Using heat sensors mounted on their own cars or bikes, community volunteers, led by a team of local partners in each city, will traverse their neighborhoods morning, afternoon, and evening on one of the hottest days of the year. The sensors will record temperature, humidity, time, and the volunteers’ location every second. NOAA’s National Weather Service will provide forecasts to help the communities plan their campaigns.

April Rose from the City of Austin’s Forestry Division was part of the volunteer team that collected temperature data in the Austin, Texas area last summer to help produce urban heat maps for the community. Credit: City of Austin

By working with communities, the campaigns will raise awareness among volunteers and residents about heat risk, incorporate local perspectives to produce heat maps, and engage communities in pursuing solutions. 

Cities from past campaigns have used the heat maps to inform heat-mitigation decisions, educate residents and policymakers, and direct research on effective solutions. The city of Houston, Texas incorporated the mapping results into its Climate Action Plan. The city of Richmond, Virginia used data from the heat island campaign to turn city-owned land into new community green spaces.

“Communities are taking action to manage dangerous extreme heat that’s impacting their families and neighbors,” said Hunter Jones, Climate and Health Project Manager with NOAA’s Climate Program Office. “As climate change brings worsening heat waves, the information from these campaigns will help bring local and equitable solutions to those facing the greatest threat.”

Addressing an unequal heat risk

On top of climate change, cityscapes worsen extreme heat’s heavy toll. Known as the “urban heat island effect,” paved, dark surfaces, like roads and buildings, absorb and radiate more heat than natural landscapes with trees and grass, driving up local temperatures.

According to a recent nationwide study spurred by past NOAA and partner heat island campaign efforts, neighborhoods subjected to historical redlining typically lack green space and suffer most from urban heat islands. The study found that 94% of formerly redlined areas, which remain mostly lower income communities of color, are exposed to higher temperatures than non-redlined, affluent areas.

“The mapping campaigns provide a roadmap to help communities alleviate these disparities by identifying specific locations where heat-mitigating interventions could save lives,” said Vivek Shandas, study co-author and Portland State University Climate Adaptation Professor. 

To keep up with the summer 2021 campaigns, subscribe to the Heat Beat Newsletter, check out the National Integrated Heat Health Information System website, or follow #UrbanHeatMaps2021on social media.

Go online for more information on health resources for extreme heat and access urban heat mapping data from past campaigns.


The urban heat island mapping campaign is supported by NOAA’s Climate Program Office (CPO) through its National Integrated Heat Health Information System (NIHHIS)  — a NOAA and Centers for Disease Control and Prevention effort — and Communication, Education, and Engagement Division. NIHHIS is funding, in part, nine campaigns and partnering with four that have secured independent funding. The campaigns are jointly coordinated by NIHHIS and CAPA Strategies LLC.


Citizen scientists take to the streets to map the hottest places in ten U.S. cities 24 July 2019

Citizen scientists take to the streets to map the hottest places in ten U.S. cities

With specially designed sensors mounted on their own cars, volunteers in each city will drive pre-planned routes, recording heat and humidity as they go. Scientists will stitch their results into a detailed map showing the hottest parts of each city.

National Geographic highlights NOAA-funded Urban Heat Island project with 2019 campaign set to kick off Saturday 24 July 2019

National Geographic highlights NOAA-funded Urban Heat Island project with 2019 campaign set to kick off Saturday

Developing an Early Warning System to Prevent Heat Illness

As three cities gear up to map urban heat islands on Saturday, this week National Geographic shared an article highlighting the NOAA-funded 2018 summer mapping campaign to help address extreme heat. The article includes the project’s map of Washington, DC, in August 2018 where temperatures spanned almost 17 degrees between the hottest and coolest areas of the city.

RCCC Heatwave Guide for Cities 24 July 2019

RCCC Heatwave Guide for Cities

This guide is intended to help city governments understand the heat risks they face, develop an early-warning system, work with partners to consolidate action plans, and adapt urban-planning practices.

Citizen Scientists Take to the Streets to Map the Hottest Places in Ten U.S. Cities 24 July 2019

Citizen Scientists Take to the Streets to Map the Hottest Places in Ten U.S. Cities

Citizen scientists will take to the streets during the hottest days this summer to map hot spots in ten different U.S. cities. The campaign is part of a NOAA-funded project to map places where buildings, asphalt, and other parts of urban environments can amplify high temperatures, putting people at heightened risk of heat illness during extreme heat events.

June 2019 was hottest on record for the globe 18 July 2019

June 2019 was hottest on record for the globe

Antarctic sea ice coverage shrank to new record low

Schools are letting out, Memorial Day is nearly here, and for many Americans that means the unofficial start of summer. And if it's summer, then it 's time to start paying attention to the risk of extreme heat. According to NOAA’s summer outlook, most of the United States is favored to have a hotter than average summer in 2017. Only in the Great Plains do forecasters think the chances for a cool or a normal summer are equal to the chances of a hot summer. Everywhere else—from Alaska to southern California, and from Maine to Texas—odds are tilted toward well above average warmth. The absolute highest chances for a much warmer than usual summer are in Hawaii. (see the large version of the map below for Hawaii and Alaska.



NIHHIS is made possible by our participating agencies.





Department of Agriculture Forest Service






NIHHIS Headquarters

Address: 1315 East-West Hwy, Suite 1100
Silver Spring, MD 20910

About Us

NIHHIS is an integrated information system that builds understanding of the problem of extreme heat, defines demand for climate services that enhance societal resilience, develops science-based products and services from a sustained climate science research program, and improves capacity, communication, and societal understanding of the problem in order to reduce morbidity and mortality due to extreme heat.  NIHHIS is a jointly developed system by the Centers for Disease Control and Prevention (CDC) and the National Oceanic and Atmospheric Administration.

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