Measured ozone and temperature vertical profiles from Thessaloniki, Greece, were used together with the mid-latitude standard profiles as input data in a radiative transfer model. Calculations of direct and global solar irradiance, actinic flux, UV-B and CIE weighted integrals for solar zenith angles of 30°, 70° and 85° were performed and analyzed. Variable temperature values and ozone redistribution may change UV radiation reaching the surface significantly more than the proposed measurement uncertainties for high solar zenith angles. A specific measured profile corresponding to air masses of polar origin probed over Thessaloniki was selected and the differences in vertical distribution of UV-B radiation were discussed. Obtained results revealed that the use of an inappropriate temperature and ozone profile may lead to significant changes at small UV-B wavelengths and high solar zenith angles. In this case, the use of seasonal average vertical profiles of ozone and temperature for a given area may be carefully utilized when accurate model spectral calculations are needed and comparison with measurements in the troposphere performed.