The paper deals with assessment of impact of freezing-thawing process on slope stability. Numerical simulation with using coupled thermal–hydraulic–mechanical analysis (software “Geostudio 2012”, Canada) was implemented to make accurate time-dependent forecast of safety factor and defined probable slope failure mechanism of earth structures in cold climate. Results of modelling showed safety factor value was decreased from 2.15 to 1.13 when earth structure's slope is thawing. Significant increase of hydraulic gradient (from 0.1 to 14) was observed in the toe of dam.