The paper presents a comparison of three selected models: Turc’s formula, modification of Turc’s monthly formula, and linear model for assessing potential evaporation (i.e. evaporation from water surface) for the cold half-year period. Analyses were carried using 35-year long monthly data of potential evaporation, mean air temperature and solar radiation. Modification of Turc’s formula was made by parameterisation of equation and introducing an additional coefficient. Parameter estimation of all presented models was done by the least square method. Test of new formulae for winter months has shown lower errors, depending on considered month.