Samsun has a typical Black Sea climate with high and evenly distributed rainfall the year round. Summers are warm and humid, and the average maximum temperature is around 27 °C (81 °F) in August. Winters are cool and damp, and the lowest average minimum temperature is around 3 °C(37 °F) in January.
Precipitation is heaviest in late autumn and early winter. Snow is quite common between the months of December and March but this usually varies considerably from year to year, and the snowcover and temperatures below the freezing point rarely last more than a couple of days.
The water temperature, like on the rest of the Black Sea coast of Turkey, fluctuates between 8° and 20 °C (68 °F) throughout the year.