Lake Onega is relatively cold, with temperatures below for half of the year and average summer temperatures of about . The catchment area of drains into the lake via 58 rivers and more than 110 tributaries, including the Shuya, Suna, Vodla, Vytegra and Andoma. The only outgoing River Svir, which marks the southern boundary of Karelia, runs from the southwestern shore of Lake Onega to Lake Ladoga and continues as the Neva River to the Gulf of Finland. The White Sea–Baltic Canal runs through the lake from the White Sea to the Baltic Sea. The Volga–Baltic Waterway connects Onega Lake with the
Onega Bay descendants) not later than in the 12th century. The selo of Soroki, currently Belomorsk, is known from that time. Most of the villages at the Onega Bay coast such as Purnema or Unezhma (now abandoned), are old Pomor villages, many of them still depend on fishery. Solovetsky Islands are on the World Heritage list, and there is intensive passenger sea traffic to the islands, mostly originating from Kem and Belomorsk. There are also regular but infrequent passenger connections between Arkhangelsk and the villages of the Onega Peninsula. Onega Bay The Onega Bay () is located in the Republic of Karelia