Russia is washed by 13 seas of three ocean basins — the Atlantic, Arctic and Pacific. The warmest for summer swimming are the Black and Azov seas in the south (up to +24…+26 °C) and the southern Caspian. The Baltic near St. Petersburg and Kaliningrad reaches +18…+22 °C in summer, while the northern seas — Barents, White, Kara, Laptev — stay cold year-round. In the Far East the Sea of Japan and the Sea of Okhotsk warm later in the season, peaking in August. Pick a sea to see water temperature by coastal city, a daily forecast and the monthly climate norm.