Ice phenomena terms on the water bodies of Northwestern Russia

The dependence of ice phenomena (the dates of ice freeze-up and break-up) on the air temperature and geographic factors (geographic latitude, height above sea level, and average depth and area of lakes) is investigated on the basis of the data of long-term observations on the water bodies of Northwestern Russia. The regression models with rather high accuracy level are proposed not requiring a large number of input parameters unlike the deterministic models.