How Cold Is the Sea of Japan? Seasonal Temperature Guide

The Sea of Japan experiences significant temperature variations based on latitude, depth, and season. In the north, surface temperatures range from about 2°C (36°F) in February to 18°C (64°F) in August. Southern waters are warmer, averaging 10°C (50°F) in winter and 26°C (79°F) in summer. Deeper waters remain consistently colder, with bottom temperatures in the north hovering near -1.5°C (29°F) in winter and only reaching 4°C (39°F) in summer. Salinity also varies, generally higher in the north and at depth.