Ecological Systems and Devices Annotation << Back Dynamics of Very Heavy Snowfalls on Sakhalin Island for the Period 1967–2024 Kazakova E.N. The paper considers the spatio-temporal distribution of the number of very heavy snowfalls on the territory of Sakhalin Island from 1967 to 2024. The analysis of the main characteristics of such snowfalls is carried out. The periods with the highest frequency of very heavy snowfalls are determined (1967–1975, in 1988–1990 and in 2010–2014). The average number of such snowfalls per year is calculated, which ranges from 0.1 to 0.7. Most often, very heavy snowfalls were recorded in Yuzhno-Sakhalinsk and Poronaysk, and the snowfall with the highest intensity was in Ilyinsky (25.11.1988, 108.8 mm in 12 hours). An analysis of the intensity of very heavy snowfalls was conducted. Snowfalls with the highest intensity (more than 50 mm in 12 hours) were recorded in the southern part of Sakhalin – in Nevelsk, Yuzhno-Sakhalinsk and Ilyinsky on 25.11.1988. It was found that there are no clear dependencies in the spatio-temporal distribution of very heavy snowfalls on the territory of Sakhalin during the study period. Keywords: snow, snowfall, dangerous meteorological phenomena, Sakhalin. DOI: 10.25791/esip.6.2025.1524 Pp. 03-09.