AbstractAnnual and monthly values of sunshine duration at thirty‐seven stations in Greece are examined with the three factors of latitude, longitude and altitude by means of stepwise multiple regression analysis. The validity of the assumption that there is a linear relationship between the mean values of sunshine duration and these three factors is examined. A seasonal variation is evident in all the computed gradients of the sunshine duration, with altitude effects being at a maximum in summer, whereas the effects of latitude were most pronounced during the cold season. The thirteen empirical formulae produced do not account completely for all the variability in the data, but the resultant correlation coefficients range from 0.830 to 0.906. The residuals (i.e. differences) between actual and calculated values of sunshine duration are shown on representative maps which may be used (with the regression equations) to estimate sunshine at any locality in Greec