Ultraviolet (UV) total solar irradiation, 290–385 nm (UVT), at ground level in Valladolid, Spain (lat. 41°40′N, long. 4°50′W and 840 m a.s.l.), has been recorded from February 2001 to June 2008. The temporal evolution of the UVT irradiation follows a sinusoidal pattern with maximums in summer and minimums in winter. A complete statistical study of hourly and daily values of UVT solar irradiation has been carried out. The resul...

Several empirical models of hourly ultraviolet total radiation (UVT) have been proposed in this study. Measurements of UVT radiation, 290–385 nm, have been recorded at ground level from February 2001 to June 2008 in Valladolid, Spain (latitude 41°40′N, longitude 4°50′W and 840 m a.s.l.). The empirical models have emerged due to the lack of some radiometric variables in measuring stations. Hence, good forecasts of them can be o...