The vulnerability to thermal stress, one of the main causes of human discomfort, may be one of the key elements in urban centers in hot climates. In this scenario, the urban forestry is considered one of the tools for mitigating this effect, in the urban environment. For this purpose, this tool needs for more information about the consequence that the trees produce in the vicinity in terms of reduction of thermal stress and on the variability of this effect with the species and the seasons of the year. The objective of this work was to characterize and analyze the microclimate and the thermal comfort, in the vicinity of five tree species Pachira aquática Aubl.(Monguga); Mangifera indica L.(Mangueira); Caesalpinia pluviosa DC.(Sibipiruna); Syzygium malaccense (L.) Merr. & LMPerry (Jambo vermelho) e Licania tomentosa (Benth.) Fritsch (Oiti), located in the central sector of Gurupi, Tocantins in the year 2016. The considered microclimatic variables were: temperature, relative humidity, and wind speed; recorded through a portable weather station, brand Skymaster, Model SM-28, at distances: 0 m (shade), 5 m, 10 m and 15 m (sun) from the shaft of the tree, at 10:00 h, 12:00 h and 14:00 h. The characterization of thermal comfort was based on the heat index and Olgyay bioclimatic chart adapted for hot climates. All variables were considered in the space affected by the tree effect and analyzed statistically. Regarding the heat index, the mean of the study was 34±1.1°C, categorized as "extreme caution", while in the wet period from october to december the average was close to the category: "caution". There were also observed attenuations of 0.5°C and 2°C between the shade and the sun, with probabilities of 0.76 and 0.53, respectively. Of the studied species, Mangueira contributed the most to attenuations of 0.5ºC (p=0.92) and 2ºC (p=0.67). The dry period was analyzed particularly as being considered thermally critical, with prominence of the species Oiti, Mangueira and Sibipiruna. Regarding the thermal comfort it was shown by the chart of Olgyay that in shade comfort can be reached providing winds higher than 1ms-1. From the results can be inferred positive effects of all the trees present in the urban arborization with the characteristics of the studied species.
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