A Sacramento County study found that city-wide maximum mid-day air temperature reductions due to the shading and evapotranspiration of trees are in the range of 0.04°C to 0.2°C per percent canopy cover increase.
Simpson, James R. (1998). Urban forest impacts on regional cooling and heating energy use: Sacramento County case study. Journal of Arboriculture, 24, 201-214.
