These are the 5 US cities with the most people living in urban heat islands
An estimated 41 million people in major U.S. cities experience temperatures that are at least 8 degrees warmer than those felt by people living outside the cities.
The climate communications group Climate Central studied 44 major cities across the country, ranging in size from Wichita, Kansas, with a population of about 554,000, to New York City, with a population of more than 9 million. The group also refined their research within the cities by using census tracts to zoom in and learn about populations within specific districts.
For each of the cities, researchers calculated an urban heat island (UHI) index, which measures the difference in temperature between urban areas and rural areas. Because many urban areas are warmer than the surrounding rural areas, they are often referred to as "urban heat islands."
A graphic showing the temperature differences between rural, industrial, urban, park and suburban areas. (Climate Central / FOX Weather)
Key factors contributing to the creation of urban heat islands include miles of hard and dark surfaces, population density, less vegetation and buildings that impact airflow in cities, according to Climate Central.
The group found that of the 74 million people within the study’s analysis, about 55%, or 41 million, lived in areas with a UHI index of 8 degrees or higher. This means that when the temperature in a rural area outside a city is 90 degrees, it is closer to 98 degrees or higher for many people in the city.
Here are the five cities with the highest UHI indices, according to their study.
1. New York City
The most populous city in the country, New York City, has the highest number of residents living with a UHI index of 8 degrees or higher. About 78% of the population, or more than 7 million people, are affected.
This photo taken on June 21, 2023 shows a temperature display reading 99 degrees Fahrenheit about 37.2 degrees Celsius in late afternoon in Houston, Texas, the United States. (Photo by Chen Chen/Xinhua via Getty Images)
2. Houston
The fourth-largest city in the nation and the largest city in Texas, Houston has an estimated 4.2 million people living in an area with a UHI index of 8 degrees or higher. This translates to about 73% of the total population of Houston.
3. Los Angeles
The largest city in California and the second-largest city in the country, Los Angeles has about 3.2 million people living in an area with a UHI index of 8 degrees or higher. This translates to about 45% of the total population of Los Angeles.
4. Dallas
Back in Texas, Dallas has nearly 2.2 million people living in an area with a UHI index of 8 degrees or higher. This translates to about 75% of the city’s total population.
5. Chicago
The largest city in Illinois has more than 2 million people living in an area with a UHI index of 8 degrees or higher. This translates to about 52% of the city’s total population.
At the bottom of the list was Wichita, which has an average UHI index per capita of 7.2 degrees.
To view the full list of cities that were part of this study, check out this document by Climate Central.
This week, a heat wave is spreading across the nation, with about 75% of the nation's population experiencing warmer-than-average temperatures through Friday.