Global spectral UV-B measurements performed at Reykjavik (64 degree(s)N), Iceland since November 1991 are used in this work to study the influence of changes in total ozone on the UV-B solar radiation reaching the earth's surface at high latitudes, under variable weather conditions. The measured UV-B levels during the winter-spring season of 1992 are compared with those of the same season in 1993, during which significantly low ozone values were observed. This comparison shows increases in solar UV-B fluxes at ground level of as high as 40%. Also, the UV-B variability during summer time, when prolonged daylight exists, is studied. The broad range of total ozone levels measured during the period of study allows the calculation of the UV-B amplification factor due to changes in total ozone at different solar zenith angles which were found to range between about 2 and 4.