In a desert city such as Phoenix, summertime heat is a way of life, but how much does the built environment contribute to the intensity of the heat on a summer night? In urbanized Phoenix, nights don’t cool down as much as in the surrounding rural areas and on more and more summer nights, the official Phoenix temperature fails to drop below 90 degrees. Climate plays a huge role in the comfort and quality of life of residents, with numerous implications for tourism, energy demand, water use, and the vulnerability of low-income families.

During the mid-part of the last decade, when the population growth rate was at its highest, the Phoenix area experienced rapid development and urban sprawl. The result has been an intensification of the Urban Heat Island effect. In this edition of Decades, author Sally Wittlinger discusses this uncomfortable consequence of urbanization.