Noise exposure in urban areas is an important factor which influences the quality of life of urban residents. Particularly in residential areas near main roads this problem is essential, because prescribed noise levels are often exceeded here. When analysing this problem, the influence of the atmospheric structure on sound propagation under specific urban environmental conditions has to be investigated, especially for longer sound paths. Thereby, the high variability of meteorological quantities like temperature and wind vector induces an increased or decreased noise exposure. To operationally answer questions of noise protection, the sound propagation model of the atmosphere using ray-tracing (SMART) has been further developed. In the present study, this model was enhanced to allow simulations of outdoor sound propagation in urban areas. Thereby, investigations of the dependency of the sound propagation on temporally variable weather conditions under the special urban influence were performed.