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The Urban Heat Island Effect

For most large cities in the U.S., urban zones are warming at twice the rate of rural zones. Dallas is heating up faster than any other large city in the country, except for Louisville, Kentucky, and Phoenix, Arizona. Why? There is more than 35% impervious surface in the city! Impervious surface is any surface that blocks rainwater from going into the ground. 

The hottest areas of Dallas measure an average high of 101°F and low of nearly 80°F for five full months of the year. Dallas urban areas can be as much as 12 degrees F hotter than surrounding rural areas.  Rural farmland areas have the coolest temperatures, around 85 degrees, while city centers can be around 93 degrees. Another notably cool area is the park. We can attribute these cooler areas to being composed of greenery and having less structures that retain heat. 

As a solution to this problem, Texas Trees Foundation is an urban forestry non-profit focused on preserving and expanding public parks and green spaces in the community and educating others about the importance of the urban forest. According to their research, tree planting and preservation was found to be more than 3.5x as effective in lowering temperatures as cool materials strategies, which is also another viable solution.

Urban Heat Islands

Download a PDF of the infographic above. 

Ashlee Gardner

Ashlee Gardner

Ashlee Gardner was born and raised in the great state of Texas, where she currently resides in the Dallas-Fort Worth area. She earned a Master of Science in Biology from the University of Texas at Arlington and a Bachelor of Arts from the University of Texas at Tyler. 

She is a former high school agriculture science teacher with Dallas ISD, where her school focused on urban agriculture and environmental sustainability. She is now a healthy living research specialist with the Institute of Advancing Health through Agriculture at the Texas A&M AgriLife Research Center in Dallas.  

Her research interests include project-based learning and informal STEM learning. In her spare time, she enjoys traveling and trying new foods!

Participant School & Location:

Research Specialist, Institute for Advancing Health through Agriculture (IHA)
Texas A&M AgriLife Research Center
Dallas, Texas

Use the interactive below to learn more about urban heat islands.