In the field of architecture, solar engineering, summer cooling, etc, it is often necessary to conduct simulations in order to predict or to assess the performance of a building, a solar system, or an installation. These processes require input data representative of the local climate, often on a hourly time step and for the 3 solar radiation components. When these input data are missing, it is necessary to evaluate or to generate them by means of software, or to derive them from satellite images. Meteonorm (www.meteotest.ch) is one of these software. It makes it possible to generate hourly climatic time series for a location situated anywhere over the world, based on an internal averaged data bank, or on real monthly mean values downloaded from the Internet. A limited study on the 3 summer months when air-conditioning can be necessary was already published, based on temperature and radiation measurements conducted in the Geneva region, and on data generated by Meteonorm. The purpose of this study is to carry out a more thorough validation of the radiation parameters produced by Meteonorm.