60 Largest Cities
- An analysis of the 60 largest U.S. cities found an average of 8 more days above 90 degrees than surrounding rural areas.
- 57 cities had measurable heat island effects over the past 10 years with an average of 2.4 degrees F warmer, with Las Vegas averaging 7.3 degrees, Washington, DC 4.7 degrees, and Kansas City 4.6 degrees.
- Evapotranspiration, the return of water vapor from trees and other vegetation to the atmosphere, alone or in combination with shading of buildings can help reduce peak
summer temperatures by 2–9°F.
- Larger patches of forest have a greater impact on temperature than isolated trees.