Outdoor thermal environments within urban areas are formed by a combination of meso-scale meteorological conditions above the urban area and the urban characteristics (e.g., the shape and arrangement of buildings, the green cover ratio, and the intensity of anthropogenic heat release). Within urban areas, the thermal environment is often severer than the condition above the urban areas due to the urban characteristics. This study aims to develop a new prediction system for assessing the effects of meteorological conditions at global scale on the human physiological response in outdoor urban area by combining meso-scale meteorological model, large-eddy simulation and human physiological model. Based on the proposed method, future change of thermal environment within a modeled district in Tokyo Metropolitan area for typical summer days of 2010s’ and 2050s’ summer was evaluated.