The article describes a model to derive hourly maps of tropospheric ozone distribution out of ozone monitoring network data within mountainous areas. This method is based on the fact that there is a strong dependence of tropospheric (ground level) ozone concentrations on relative altitude above the valleys that is changing daily and hourly. The core of the model is an elevation/daytime-dependence function that is automatically parameterised by day-specific monitoring data. Using this function and a digital elevation model ozone concentration surfaces can be modeled for every specific hour throughout the summer-half-year. Remaining local deviations of the monitored data are interpolated and added as deviation surface to the ozone concentration surface. Hourly available model results include the seasonal and day-specific influences as well as the regional influences caused by local emission - or weather situations. Validity tests show that the spatio-temporal dynamics of ground level ozone concentrations were calculated with high accuracy and spatial resolution. The model is applied since 1992 to create hourly maps of day specific ozone distribution maps for Austria. Since summer 1995 the model is integrated into the ''Austrian Ozone Monitoring Network''-visualisation interface and maps are published by the Federal Environment Agency Austria as WWW-pages for every day.