Different tree species, and their distribution in urban areas, can help improve thermal microclimate and promote human thermal comfort in these environments. The aim of the current study is to investigate how different tree species and their distribution in urban areas can help improve human thermal comfort in built environments. Firstly, the thermal comfort provided by different tree species, and by their planting design (individuals and clusters), was measured at the free flat area of Campinas County, Brazil. Then, human thermal comfort provided by trees in urban areas (low and high-density construction areas) of Campinas and Santos counties, Brazil, were measured. Benefits provided by the following twelve species were analyzed from 2007 to 2010: Tabebuia chrysotricha (Mart. ex DC.) Stand., Jacaranda mimosaefolia D. Don., Syzygium cumini L., Mangifera indica L., Pinus palustris L. and Pinus coulteri L.—individuals; Lafoensia glyptocarpa L., Caesalpinia pluviosa F., Spathodea campanulata P.Beauv. , Tipuana tipu F. (individuals and clusters) –, Delonix indica F. and Senna siamea L. (clusters). C. pluviosa F. was capable of reducing the Physiologically Equivalent Temperature (PET) to ranges between 12 and 16° C, for individual trees; and between 12.5 and 14.5° C, for clusters. Streets with shading trees recorded PET decrease by 18° C in low-density areas, as well as by 10° C in high-density areas. Trees planted in high-density areas can also help mitigate the negative effects of heat on facades, in addition to increase the aesthetic effect of streets. Trees planted in low-density areas can help improve thermal comfort for pedestrians and cyclists.