The KCl:Eu2+ system response to UV-C was investigated by analyzing the optically stimulated luminescence (OSL) and thermo-luminescence (TL) signal produced by ultraviolet light exposure at room temperature. It was found that after UV-C irradiation, OSL was produced on a wide band of visible wavelengths with decay time that varied by several orders of magnitude depending on the Eu2+ aggregation state. In spite of the low intensity of solar UV-C reaching the Earth's surface in Madrid (40o N, 700 m a.s.l.), it was possible to measure the UV-C radiation dose at 6:48 solar time by using the TL response of the KCl:Eu2+ system and differentiate it from the ambient beta radiation dose. © 2009 The Chinese Society of Rare Earths.