The Japan resorts with the warmest sea water temperature in May are Okinawa, Nagasaki and Tokyo.
Below you can see a list of all popular Japan resorts and information about sea water temperature in May for the last two years.
| Resort Name | May 2026 | May 2025 | May 2024 |
|---|---|---|---|
| Okinawa | 78.2°F | 79.1°F | 79.7°F |
| Nagasaki | 71.2°F | 67.8°F | 68.9°F |
| Tokyo | 71.1°F | 68.6°F | 69.9°F |
| Fukuoka | 70.8°F | 66.3°F | 68.6°F |
| Yokohama | 70.5°F | 67.8°F | 69.2°F |
| Nagoya | 70.0°F | 67.6°F | 68.5°F |
| Kyoto | 69.7°F | 66.5°F | 66.9°F |
| Kamakura | 69.6°F | 67.4°F | 68.7°F |
| Atami | 69.0°F | 67.0°F | 68.9°F |
| Nara | 68.9°F | 66.6°F | 66.4°F |
| Hakone | 68.9°F | 67.2°F | 68.8°F |
| Osaka | 68.3°F | 66.7°F | 66.2°F |
| Kobe | 67.3°F | 65.7°F | 65.1°F |
| Hiroshima | 66.2°F | 64.4°F | 64.7°F |
| Sapporo | 52.4°F | 52.7°F | 53.0°F |
| Noboribetsu | 47.6°F | 48.3°F | 49.2°F |
Please see following sea water temperature averages charts for the warmest Japan resorts in May.
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.
