They bring cold air from the south, establishing the temperature of about −15 °C (February) over most of the sea. The northern part is warmer at about −9 °C, sometimes reaching −6 °C, due to the warm air masses from the Atlantic.
This is just on the month of February?
Yes during winter months. The White Sea coast is not yet warm enough for swimming and does not exceed 20°C. The warmest water temperature White Sea today is 20°C (in Arkhangelsk), and the coldest White Sea surface temperature now is 8.1°C (in Solovetsky Islands).