Improving outdoor thermal comfort is a key parameter in achieving the vitality and functionality of urban spaces. In order to build a thermally comfortable outdoor space, designers must consider suistainable urban, architectural, and landscape design solutions. The main problem is that most of recent developments in Egypt didn't consider the use of green design strategies which resulted in human outdoor thermal discomfort. In this research, a case study in Egypt, characterised by hot arid climate is used to discuss and quantify the impact of green design strategies on urban microclimate and human sense of thermal comfort. The methodology used is based on Envi-met simulation to measure the four climatic parameters and PMV index. The outcomes indicated that significant enhancement in thermal comfort was achieved with the trees coverage, Where Using the maximum tree coverage showed the best improvement in PMV values with a drop of 2.48 at peak hours when compared to the base case. The results showed that the use of trees is an important strategy to improve the micro-climatic conditions and human thermal comfort in open spaces due to the shading effect as they block out excessive solar radiation.