Urban areas both generate and trap heat. In urban areas trees are cut down to make room for commercial growth. On a hot summer day certain parts of urban areas can be warmer than its surrounding areas. These are areas where there are fewer trees, shrubs, and other plants to shade buildings, intercept solar radiation, and cool the air.

Here the materials used to make the buildings do not reflect but absorb the sun’s rays. Scientists have named such places “Urban Heat Islands.” Satellite readings from NASA have shown average temperature in cities to be 5 to 10 degrees Fahrenheit hotter than surrounding areas. See Sketch of an Urban HeatIsland Profile.