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.