Ground-level ozone is an air pollutant that, despite reductions in precursor emission in Europe, still represents a risk to vegetation and human health. This study is based on observations of ozone concentrations ([O-3]) from 25 European monitoring stations, north of the Alps within the EMEP network, during the 26-year period from 1990-2015. We analyzed the maximum and minimum hourly [O-3] as well as the seasonal cycle in relation to latitude. In addition, temporal trends were studied. The maximum [O-3] increased towards the south of the study area, while the yearly minimum of daytime mean increased towards the north. There was a strong correlation between the day of year when the maximum [O-3] occurred and latitude: the maximum [O-3] occurred earlier in the north. The maximum daytime [O-3] decreased at all stations while the minimum daytime [O-3] increased at most stations during the studied time period.