The snow cover in Belgium has been characterized by six variables : the date of the first snow cover, the date of the last snow cover, the duration of the snow lying season, the number of days with snow lying, the longest period of consecutive days with snow lying and the maximum depth of the snow cover. The date gathered at the Belgian airports have been investigated and probability functions have been adjusted. Moreover the accuracy of the estimation of the parameters of these probability functions has been improved by taking into account : (1)the correlation between regional data and the corresponding observations of Bruxelles-Uccle for which the considered distributions are well known; (2)the existence of linear relationships between the values of these parameters and the variation of altitude in Belgium. In order to enable a general use of this method of estimation, a new form has been given to the distribution functions of the number of days with snow cover and of the longest period of consecutive days with snow cover at Uccle.