Natural ventilation is an efficient way of removing high internal heat gains for buildings and its energy saving potentials however depend on many parameters. This presentation reports a series of GIS maps for natural ventilation potentials of North America, similar to the well-known solar potential maps. These maps provide key graphical information of energy saving potentials of both single sided and cross natural ventilation in terms of total hours suitable for natural ventilation and associated energy savings for over 50 cities in the US and 10 cites in Canada.