Skip to main content

NOAA Releases New Tool to Help Prepare and Protect Vulnerable Populations from Extreme Heat

October 30, 2017
Map of the Continental U.S. with scoring according to socioeconomic status, disability, minority status, household composition

Unusually hot days are becoming much more common. Prolonged periods of these unusually hot days - known as heat waves - are serious weather phenomena that can be deadly. Heat wave length, intensity, and frequency are all expected to continue increasing, posing a pressing public health concern both in the US and around the globe. This new tool is designed to communicate the risk of extreme heat and support planning on multiple time scales to reduce health risks.



On behalf of the National Integrated Heat Health Information System (NIHHIS) researchers at NOAA and ESRI have developed a new tool in an effort to plan and prepare for the increasing extreme heat we are witnessing. This is a new set of visualizations and analytical tools to understand, prepare for, and respond to extreme heat and its human health impacts (including economic impacts). The story map includes a number of powerful tools which can also be used as stand-alone analytical web apps. Innovatively, this digital product uses temperature projections and social indexes to identify vulnerable populations that might be exposed to dangerous heat in the future. It includes layers that help decision makers understand and compare their options for reducing risk, such as locations of cooling centers and health care facilities, or where to improve the urban tree canopy. It also provides access to view and share heat action plans around the world.

To see the US cities identified as most vulnerable go to the interactive map here:


The Dangers of Heat Waves

The combination of a warmer climate, an aging U.S. population, and a greater number of people living in urban areas increases the vulnerability of the U.S. population to extreme heat.Older adults and children have a higher risk of dying or becoming ill due to extreme heat. Also, people working outdoors, the socially isolated and economically disadvantaged, those with chronic illnesses, those without air conditioning, as well as some communities of color are all especially vulnerable to death or illness.

With about 130 deaths each year, heat causes more deaths than flooding, lightning, tornadoes, hurricanes, or cold.

From 2006-2010, 3,332 U.S. residents died from exposure to extreme heat, or about 670 deaths annually. An assessment of 43 U.S. cities from 1987 to 2005 found a 3.7 percent increase in mortality during heat waves. Early season heatwaves increased the incidence of mortality by 5 percent. Even a 1°F increase during a heat wave causes significantly more deaths.

Below is a map of the average heat season temperatures during Summer 2017, compared with the average temperatures for the last 100 years.


Map of the Continental U.S. with divisional average temperatures between March-August, 1895-2017.


Understanding this new weather reality is crucial not only for the US population but also for vulnerable communities around the globe. In 2015 for example, 2,330 people died in a heat wave in India with temperatures reaching 48 degrees Celsius (118 degrees Fahrenheit). Even the roads started melting.

Understanding Who is at Risk

Using the Center for Disease Control and Prevention's 2014 Social Vulnerability Index, we can see which areas of the US have heightened vulnerability based on socioeconomic status, household composition and disability, minority status and language, and housing and transportation.

Explore the interactive tool here:

Extreme heat is also hard on the built environment that we rely on for transportation of goods and people. Many of the infrastructure impacts can cause loss of life, but also loss of goods/disruption to supply chains and impacts to livelihoods.To help understand how hotter days are affecting the economic centers in the US the NOAA and ESRI also developed this map:


Map of the Continental U.S. with the places where high heat days have been most common so far (the cumulative number of heat alerts issued in that place since 2005). The purple symbols show Gross Domestic Product (GDP) by metropolitan area in the US as of 2015.


This map shows the places where high heat days have been most common so far (the cumulative number of heat alerts issued in that place since 2005). The purple symbols show Gross Domestic Product (GDP) by metropolitan area in the US as of 2015. The Eastern Seaboard from New York to Georgia, as well as much of the Midwest from Columbus to east of Kansas City to south of Memphis, as well as the greater Las Vegas & Phoenix areas have all had over 73 heat alerts issued. Archived National Weather Service alerts are aggregated, continuously updated, and made available for download by Iowa State University's Iowa Environmental Mesonet.

To learn more about what is being done and what more we can do to help, click here

The National Integrated Heat Health Information System (NIHHIS) was created to address the increase of heat extremes now and into the future. NOAA’s Climate Program Office leads NIHHIS in partnership with the Centers for Disease Control (CDC) to improve understanding and reduce impacts of extreme heat events across various time scales, build capacity across climate and public health communities, and develop timely and accessible communication tools to inform preparedness and adaptation.