What Are Urban Heat Islands

Urban heat islands (UHI) are a consequence of our modern, developed societies. The term describes the phenomena whereby built-up urban areas are 2–5°F hotter than nearby rural areas. This results from the construction of buildings, roads, and other forms of infrastructure on areas where trees and other vegetation once stood. The types (non-porous) and colors (dark) of popular construction materials contribute to this issue because they absorb and retain more heat, and for longer periods of time, than natural materials. Therefore, urban heat islands adversely affect local communities and the environment in a number of ways, including:

  • Increased summertime peak electrical energy demand
  • Increased amounts of air pollution
  • Increased greenhouse gas emissions
  • Greater occurrence of heat-related illnesses and mortality
  • Decreased water quality
  • Altered local weather patterns

The U.S. Environmental Protection Agency (EPA) recognized this growing problem a number of years ago and has a webpage dedicated solely to UHI. The intent is to educate and empower the public about what can be done to mitigate this entirely anthropogenic issue. In particular, they outline five strategies, listed below, that could be enacted to reduce heat gain due to urbanization:

  • Planting trees and other vegetative cover
  • Installing green roofs
  • Installing cool roofs
  • Utilizing cool pavements for roadways
  • Smart growth and development programs


Local community organizations spearhead many of the grassroots efforts to replant trees and other forms of vegetation to UHI-affected cities. However, larger projects, such as the engineering and construction of a green roof on top of an existing structure, must be undertaken by properly trained & highly skilled construction professionals.

The Coalition for Responsible Equitable Economic Development (CREED LA) fights to ensure that developers pay fair wages to the hard working men & women throughout the construction trades while simultaneously providing them with quality health care, continued training, and trustworthy retirement plans. As a result, CREED LA proudly supports environmentally-responsible projects throughout Los Angeles that not only have a positive impact on the local community, but support LA’s working families as well. To learn more about how our non-profit organization supports those building a better world for us all, contact Jeff Modrzejewski at (877) 810-7473.