This paper aims to investigate the hygrothermal behavior of direct green facades and assess their efficiency under semi-arid climate. For that purpose, a comparative study was conducted in three buildings; two buildings with direct green façades (covered with deciduous climbing plants) and one with a bare façade. Air and surface temperature, relative humidity and wind speed were collected in situ and several factors were taken into consideration as thickness and density of plant cover. The analysis of measurement data revealed that direct green façades contribute to improve the outdoor and indoor thermal environment of buildings due to the effect of shading and evapotranspiration. Moreover, the different types of green façades illustrated their different heat impact on the thermal environment of buildings depending on the density and thickness of the plant layer and the covering ratio.