The intensity of Urban Heat Islands (UHI) changes due to seasonal and non-seasonal characteristics,which can vary slightly from hour to hour and significantly from daytime to nighttime.UHI can exhibit single- center,multi-center,strip,radiation and reticulation horizontal spatial distribution patterns,while vertical spatial distributions are very obvious.Many of the findings regarding relationships between the intensity of the urban heat island and various effects are summarized in this review paper.The main causes are listed as:(1) heating emission from buildings (i.e.commercial and residential heating); (2) absorption and radiation qualities of surface materials (i.e.asphalt,concrete,pavement) and building materials;(3) minimal urban vegetation and subsequent low evapotranspiration rates; (4) atmospheric pollution; (5) urban morphology;(6) variable sensitivity to cloud cover,wind,and local topography.