(NEXSTAR/WKRN) – Does it feel like a totally different climate when you go across town? It may be the urban heat island effect.
The way a city is designed can make hot weather feel even worse. The temperature on your block is influenced by everything from the number of trees on the street to the color of the pavement. When trees and vegetation (which absorb heat) are replaced by buildings and roads (which can radiate heat), it feels hotter.
“The heat island effect can result in significant temperature differences between rural and urban areas,” explained the Environmental Protection Agency (EPA).
Climate Central, an organization of scientists and journalists focused on studying the impacts of climate change, broke down 44 cities into Census blocks to determine which neighborhoods suffer from the worst urban heat effects.
In some cities, like Indianapolis, Albuquerque and San Jose, the worst impacts are concentrated in the cities’ downtown cores. In other cities, like Dallas, Detroit and Phoenix, the urban heat effect is spread throughout.
For each census tract, Climate Central researchers determined the urban heat index, which shows how much hotter it feels in those neighborhoods because of the built environment. The city with the worst urban heat index was New York, the analysis found.
In New York, nearly 80% of residents live in a Census tract where the urban heat effect is 8 degrees or higher – “meaning that on a day when temperatures in a park outside the city are 90°F, it feels like 98°F or higher,” the report explained.
The map of hot spots around New York shows lots of neighborhoods shaded in dark red, with relief only to be found in the park-filled parts of Queens and on Staten Island.
The urban heat index is also high per capita in Chicago, but its hottest spots are more concentrated around The Loop.
About 52% of the city’s residents experience an urban heat index of 8 degrees or higher.
Los Angeles has what Climate Central calls “sprawling heat intensity,” which means the urban heat effect happens over a vast area that is highly developed.
Downtown Los Angeles and industrial areas are worst, but there are few pockets of the massive city where you can find an urban heat effect less than 7 degrees.
Denver, with its large areas of undeveloped land, had the Census tracts with the lowest scores. The wide open spaces around Denver International Airport recorded the lowest urban heat effect.
Downtown Denver, plus the area around Standley Lake, saw the highest scores.
Over in the southeastern part of the U.S., more than 41% of residents around the Nashville area live in a Census tract where the urban heat effect is at least 8 degrees while nearly 2% live in a Census tract where the urban heat effect is at least 9 degrees.
Based on Climate Central’s map, downtown Nashville and the area around Percy Priest Lake had the highest scores. However, high levels of the heat effect were still recorded throughout other parts of Davidson County, like Antioch, South Nashville, Midtown, West Nashville, and north of downtown paralleling Interstate 65.
There are also other hot spots around Middle Tennessee, such as the southern edge of Sumner County (including Hendersonville) and the northern edge of Wilson County along the Cumberland River; the northeastern part of Rutherford County (like La Vergne and Smyrna); and a section of Williamson County (more specifically, Brentwood, an area south of Brentwood paralleling I-65, and an area north of Franklin).
Climate Matters analyzed the urban heat spots of 44 U.S. cities. (See all the maps and results here.)
The researchers also named a number of solutions – both short-term and long-term – to the urban heat problem. Planting trees can help, especially as those trees mature and grow larger to increase shade. Roof materials that reflect heat, as well as rooftop gardens, can cool things down in dense neighborhoods.
One of the hottest parts of any city is dark pavement that’s been soaking up the sun. Asphalt and concrete can even radiate heat after the sun goes down, keeping a neighborhood from cooling down at night. The EPA suggested looking into “cool pavement” technology as a solution.