The ozone layer acts as a protective shield against high-energetic solar radiation. There is evidence for a negative trend in the thickness of this layer outside the equatorial region, thus enabling more UV photons to reach the earth’s surface. As overexposure to UV radiation adversely affects humans and their environment, measures have ben taken. To stop the thinning of the ozone layer, the production of ozone depleting species is banned. Information campaigns in many countries advise against overexposure to the sun and stimulate the use of sunscreens and protective clothes when UV radiation levels are high. The UV index serves as an indicator for the amount of biologically effective UV radiation for a given time and place. Forecasting this UV index enables people to take the necessary precautions. In Belgium, the UV index forecasting system has become operational in 1998. From April to September, next day’s clear-sky UV index is disseminated to the public via the press. An evaluation of the forecasts in 1998 and 1999 is presented in this paper. As a necessary tool for UV forecasts, the total column ozone needs tot be predicted. We present a statistical approach which yields ozone forecast errors of less than 5% in 78% of the case. It is further shown that, on days with cloudiness less than 4/8, the forecasted clear-sky values differ 0.5 or less in 79% of the cases in the 1998 and 19999 forecasting season. On cloudy days, the measured UV index is generally lower than the forecasted clear-sky value.