In April warmest sea in Japan is usually observed in the following locations: Okinawa, Nagasaki, Atami.
Table below shows the average sea water temperature for marine resorts of Japan in April for the last three years.
| Place name | April 2026 | April 2025 | April 2024 |
|---|---|---|---|
| Okinawa | 74.4°F | 71.5°F | 73.4°F |
| Nagasaki | 64.0°F | 61.4°F | 63.0°F |
| Atami | 61.9°F | 60.9°F | 62.4°F |
| Tokyo | 61.8°F | 59.1°F | 60.3°F |
| Hakone | 61.7°F | 61.1°F | 62.2°F |
| Kamakura | 61.5°F | 61.1°F | 62.1°F |
| Yokohama | 61.1°F | 59.6°F | 60.5°F |
| Fukuoka | 60.0°F | 58.6°F | 60.0°F |
| Nagoya | 59.9°F | 58.4°F | 60.0°F |
| Kyoto | 59.1°F | 57.4°F | 57.8°F |
| Osaka | 59.0°F | 57.6°F | 58.7°F |
| Nara | 59.0°F | 57.4°F | 58.4°F |
| Kobe | 58.6°F | 56.5°F | 57.7°F |
| Hiroshima | 58.4°F | 57.2°F | 58.5°F |
| Sapporo | 45.9°F | 44.9°F | 44.7°F |
| Noboribetsu | 40.6°F | 42.1°F | 41.7°F |
Charts below show average sea water temperature for Japan resorts with the warmest sea in April.
You can also check other months of the year to see sea temperature of Japan resorts at that time.
Places in Japan:
Name
°F
