The Japan resorts with the warmest sea water temperature in August are Fukuoka, Kyoto and Nagasaki.
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 2026 | August 2025 | August 2024 |
|---|---|---|---|
| Fukuoka | 88.8°F | 89.1°F | 89.9°F |
| Kyoto | 88.8°F | 90.3°F | 90.2°F |
| Nagasaki | 88.7°F | 88.7°F | 89.5°F |
| Nagoya | 88.5°F | 90.4°F | 90.2°F |
| Nara | 88.4°F | 89.6°F | 89.1°F |
| Osaka | 88.1°F | 89.4°F | 88.7°F |
| Okinawa | 87.9°F | 89.3°F | 90.6°F |
| Kobe | 87.5°F | 88.6°F | 87.4°F |
| Hiroshima | 86.4°F | 86.9°F | 88.4°F |
| Tokyo | 85.6°F | 87.5°F | 88.1°F |
| Yokohama | 85.1°F | 86.4°F | 87.6°F |
| Kamakura | 84.7°F | 85.0°F | 86.5°F |
| Atami | 84.7°F | 84.2°F | 86.4°F |
| Hakone | 84.6°F | 84.3°F | 86.4°F |
| Sapporo | 77.0°F | 80.2°F | 77.4°F |
| Noboribetsu | 72.9°F | 77.6°F | 77.2°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.
