Urban Heat Islands 101

The urban heat island effect describes an increase in temperatures caused by heat absorbing surfaces in urban areas and heat-generating human activity. This guide explains how these heat islands are formed and outlines the impacts of extreme heat on public health, the economy, and the environment. It recommends that local governments reduce the urban heat island effect by increasing tree cover, investing in energy efficient buildings, installing reflective coatings on rooftops, and implementing zoning reforms that vary the height of new buildings to increase airflow.