A statistical method is presented to determine the optima design of air quality networks detecting warning and alert levels. A simulation model is used to describe temporal and spatial variations of atmospheric pollutants; air quality patterns serve as the database of the procedure to design the network. Only the sites exceeding warning and alert levels, at different meteorological scenarios, are considered as potential monitoring stations. For the selection of the optima set, spatial and temporal representativity criteria are introduced; accordingly, the optima set provides a complete representativity of the space and time considered. The method is applied to the Mestre urban area, in Venice district, for the carbon monoxide pollutant.PUBLICATION ABSTRACT