Benefits of Urban Trees Trees Modify Local Climate Trees help cool the "heat island" effect in our inner cities. These islands result from storage of thermal energy in concrete, steel and asphalt. Heat islands are 3 to 10 degrees warmer than the surrounding countryside. The collective effect of a large area of transpiring trees (evaporating water) reduces the air temperature in these areas. Trees also: Lower air temperature through shade. Increase humidity in dry climates through evaporation of moisture. Reduce glare on sunny days. Reduce wind speed. Hotter, More Glare, More Noise, More Water Runoff, More Energy Used, Harsh Landscape Cooler, Less Glare, Absorbs Noise, Less Runoff, Less Energy, More Beautiful « Return to the main page for the Benefits of Urban Trees.