The Japan resorts with the warmest sea water temperature in August are Nagoya, Kyoto and Nara.
Below you can see a list of all popular Japan resorts and information about sea water temperature in August for the last two years.
| Resort Name | August 2025 | August 2024 | August 2023 |
|---|---|---|---|
| Nagoya | 90.4°F | 90.2°F | 89.7°F |
| Kyoto | 90.3°F | 90.2°F | 89.0°F |
| Nara | 89.6°F | 89.1°F | 88.1°F |
| Osaka | 89.4°F | 88.7°F | 87.7°F |
| Okinawa | 89.3°F | 90.6°F | 86.9°F |
| Fukuoka | 89.1°F | 89.9°F | 86.5°F |
| Nagasaki | 88.7°F | 89.5°F | 87.6°F |
| Kobe | 88.6°F | 87.4°F | 86.9°F |
| Tokyo | 87.5°F | 88.1°F | 88.2°F |
| Hiroshima | 86.9°F | 88.4°F | 86.2°F |
| Yokohama | 86.4°F | 87.6°F | 87.3°F |
| Kamakura | 85.0°F | 86.5°F | 86.0°F |
| Hakone | 84.3°F | 86.4°F | 85.7°F |
| Atami | 84.2°F | 86.4°F | 85.5°F |
| Sapporo | 80.2°F | 77.4°F | 81.0°F |
| Noboribetsu | 77.6°F | 77.2°F | 77.6°F |
Please see following sea water temperature averages charts for the warmest Japan resorts in August.
You can also get the same information for the every other month of the year when the average sea water temperature is greater then 70°F.
