Okinawa’s water temperature rarely drops below 20°C (68°F), which makes Okinawa a pleasant destination all year long, even though Okinawa is seasonally subject to typhoons in June and September.
From January to May, the average water temperature in Okinawa reaches 23°C (74°F) to 24°C (75°F). During summer, the average water temperature rises to 28°C (82°F) and drops to 26°C (79°F) in autumn.
October is the best period to go scuba diving in Okinawa. The water is still warm, you will avoid the crowds, and typhoons are usually gone. Knowing what the water temperature will be at the time of your trip will help you determine if this is the best time to dive in Okinawa.
Okinawa water temperature
You will find below, month by month, the average water temperature in the main island of Okinawa:
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sept | Oct | Nov | Dec |
| 21°C 70°F | 21°C 70°F | 20°C 69°F | 21°C 71°F | 24°C 75°F | 26°C 79°F | 28°C 82°F | 28°C 83°F | 28°C 83°F | 27°C 81°F | 25°C 77°F | 24°C 75°F |
Okinawa weather data source: seatemperature.net
Ishigaki water temperature
You will find below, month by month, the average water temperature in Ishigaki Island:
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sept | Oct | Nov | Dec |
| 23°C 74°F | 23°C 74°F | 23°C 74°F | 24°C 76°F | 27°C 80°F | 28°C 83°F | 29°C 85°F | 29°C 85°F | 29°C 84°F | 27°C 81°F | 26°C 79°F | 24°C 76°F |
Ishigaki weather data source: seatemperature.net
Yonaguni water temperature
You will find below, month by month, the average water temperature in Yonaguni Island:
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sept | Oct | Nov | Dec |
| 24°C 75°F | 24°C 75°F | 24°C 75°F | 27°C 78°F | 26°C 81°F | 28°C 83°F | 28°C 83°F | 29°C 84°F | 28°C 83°F | 27°C 81°F | 26°C 79°F | 24°C 76°F |
Yonaguni weather data source: www.seatemperature.org
Other factors, of course, such as rainfall, which impacts the level of visibility underwater, must be taken into account. In this case, it is better to check Okinawa climate information.