Urban seismology, by using cultural noises that are generated by activities such as traffic, subway, social activities and are available in all places and times, describes subsurface structures and hazard analysis, and recently it has been recognized as a low-cost tool for studying the subsurface structures, improving seismic hazard management and seismic zoning (Diaz, 2017). Therefore, in the current research, urban seismology in Tehran metropolis, which is considered as one of the most populated cities in the world, has been used to investigate the minimum level of seismic ambient noise in terms of space and time. Finally, using the records of the accelerometer network of Tehran Disaster Mitigation and Management Organization and the Road, Housing and Urban Development Research Center, the lowest level of cultural noise in terms of time, according to the daytime/nighttime variation of human activities, is at 3:30-4:30 AM, and in terms of space, it is located at station D011 which takes place on a stone structure.