Manifestation of the reduction of sea ice extent in the Russian Arctic is analyzed using satellite data of 1979-2020. Observations demonstrate that in all seas there is a tendency of decrease in regional sea ice extent in summer and autumn, which is accompanied by its significant variability from year to year. In the Kara and Chukchi Seas, noticeable changes in the ice cover occurred in the time period from June to November, in the Laptev Sea and the East Siberian Sea from July to October. Comparison of daily data of 2015-2020 with the average sea ice extent in the last two decades of the previous century has shown that the destruction of the ice cover in recent years begins earlier, and its formation in autumn occurs later, changes in each of the seas having their own specifics. The largest changes in comparison with the ice conditions of the previous century are observed in the East Siberian Sea. The analysis of the sea ice conditions of the Northern Sea Route was carried out for one of the possible navigation trajectories from the group of optimal routes. The most significant changes in sea ice conditions in recent years when compared with the period 1979-1999 belong to the time interval from July to October. In July, on average, the sea ice concentration has decreased by 32 % and in October by 48 %. The most favorable sea ice conditions on the Northern Sea Route were observed in 2019 and 2020.