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Seto Inland Sea
Akashi, Japan © 708 SOM
Seto Inland Sea Water Temperature: Current & Historical Data for Coastal Resorts
We find every spot where you can swim and tell you what the water temperature is there today and throughout the year
Current water temperature
50°F
minimal
54°F
average
57°F
maximum
Graph of Water Temperature Changes in the Seto Inland Sea Over the Last 60 Days
Water temperature in the Seto Inland Sea by month
| Month | Minimum | Maximum |
|---|---|---|
| January | 48°F | 66°F |
| February | 45°F | 64°F |
| March | 45°F | 66°F |
| April | 48°F | 70°F |
| May | 52°F | 77°F |
| June | 59°F | 81°F |
| July | 66°F | 84°F |
| August | 75°F | 88°F |
| September | 72°F | 88°F |
| October | 68°F | 82°F |
| November | 59°F | 77°F |
| December | 48°F | 72°F |
What is known about the Seto Inland Sea?
Sasebo, Japan © 赤城鬼衛門The Seto Inland Sea, located between the islands of Honshu, Shikoku, and Kyushu in Japan, experiences moderate temperatures due to its semi-enclosed nature. In winter, water temperatures range from 50–57°F (10–14°C), which can feel chilly but still tolerable for more adventurous swimmers. During the warmer months, from June to September, the water warms up significantly, reaching around 73–81°F (23–27°C), making it much more inviting for swimming and water activities.
Swimming in the Seto Inland Sea is very popular, especially around islands like Naoshima and Shodoshima, where clear, calm waters and beautiful beaches attract both locals and tourists. The relatively sheltered waters of the inland sea are ideal for swimming, kayaking, and sailing. The sea is also known for its mild waves and warm temperatures in the summer, creating a perfect environment for family-friendly activities and leisurely swims. While the water conditions are generally safe, swimmers should always be cautious of occasional tidal changes and strong currents in certain areas, especially around narrow straits or near the open sea. The Seto Inland Sea offers a serene and enjoyable environment for swimming, making it a great destination for those seeking both relaxation and aquatic activities.
List of Countries Bordering the Seto Inland Sea
Popular Resorts of the Seto Inland Sea with the Warmest Water Today
Popular Resorts on the Seto Inland Sea Coast
Uwajima, Japan © 生玉理
Nearest Seas and Oceans
Frequently Asked Questions About the Seto Inland Sea
What is the water temperature in the Seto Inland Sea right now?
The water temperature in the Seto Inland Sea today ranges from 50°F (10°C) in Okayama (Japan) to 57°F (14°C) in Uwajima (Japan).
Is it possible to swim in the Seto Inland Sea?
Yes, it is possible to swim in the Seto Inland Sea, as its calm and warm waters are suitable for swimming, especially during the summer months.
In which month does the Seto Inland Sea have the highest and lowest water temperatures?
The highest water temperature in the Seto Inland Sea occurs in August, reaching 88°F (31°C), while the lowest is in February, dropping to 45°F (7°C).
Is the Seto Inland Sea colder than the Sea of Japan?
No, the Seto Inland Sea is slightly warmer than the Sea of Japan, as its average annual water temperature is 66°F (19°C), while the Sea of Japan's is 52°F (11°C).
Which countries are washed by the Seto Inland Sea?
The Seto Inland Sea washes Japan.
What are the most popular resorts located on the Seto Inland Sea?
The most popular beach destinations on the Seto Inland Sea are Kobe (Japan), Osaka (Japan), Hiroshima (Japan), Sasebo (Japan), Nagasaki (Japan), Okayama (Japan), Kunisaki (Japan), Saga (Japan), Naruto (Japan), Tokushima (Japan).
Do you have any extended or additional information about the Seto Inland Sea?
Aki-Nada is a reach in the western part of the Inland Sea of Japan. Located between the southwest of Hiroshima Prefecture and the northwest of Ehime Prefecture. Named after the historic province of Aki.
Do you have a few more photos of the the Seto Inland Sea?
Sasebo, Japan © 트립큐레이터
Sumoto, Japan © Tadao Fujikawa
Sasebo, Japan © やこ