Is the water warm near Tokyo?

The water temperature near Tokyo typically ranges from about 15°C (59°F) in spring to around 26°C (79°F) in late summer. During the peak summer months, the water can feel quite warm and comfortable for swimming. However, in the winter months, the water is noticeably cooler, averaging around 10°C (50°F). Overall, the warmth of the water varies significantly with the seasons.