In this paper, results of numerical experiments based on the one-dimensional thermodynamic model of hummock formations evolution, which has been developed by the authors, are analysed. This model has been used for computation of relative rates of freezing and melting of hummocks in typical conditions of the northeastern shelf of Sakhalin Island; then obtained values were compared with the plain sea ice cover parameters simulated by using climate and actual meteorological data. It is shown that obtained results well comply with observational data collected during expeditions in this region.