Kerama Islands Water Temperature
Updated Tue 13:07 (Asia/Tokyo)
Japan · Forecast updated Sep 22, 2026, 13:07 UTC
Current Sea Temperature
29.0°C
84.2°F
Very warm water
Valid Sep 22, 2026, 13:07 (Asia/Tokyo). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
0.8°C below
The typical September average is 29.8°C (85.6°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 29.2°C, versus 29.0°C in the prior seven days.
What to wear
Very warm water
Swimwear is usually enough; a rash guard adds sun protection.
Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions or replace the snorkel forecast.
Typical Sea Temperature Over the Year
In the historical baseline for Kerama Islands, typical monthly averages range from about 21.8°C (71.2°F) in March to 29.8°C (85.6°F) in September.
Over the past 30 days, the average sea temperature in Kerama Islands has been 28.8°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Kerama Islands, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 21.8–23.0°C | 22.3°C / 72.1°F |
| February | 21.2–22.6°C | 21.9°C / 71.4°F |
| March | 21.5–22.0°C | 21.8°C / 71.2°F |
| April | 22.2–23.4°C | 22.9°C / 73.2°F |
| May | 23.8–24.7°C | 24.4°C / 75.9°F |
| June | 26.3–27.9°C | 27.1°C / 80.8°F |
| July | 28.9–30.0°C | 29.3°C / 84.7°F |
| August | 28.4–30.5°C | 29.5°C / 85.1°F |
| September | 29.4–30.1°C | 29.8°C / 85.6°F |
| October | 27.8–29.5°C | 28.6°C / 83.5°F |
| November | 25.8–26.8°C | 26.5°C / 79.7°F |
| December | 24.2–24.3°C | 24.2°C / 75.6°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (26.21, 127.38). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
Water temperature by month
Each month uses the 2023–2025 baseline. The range is the lowest and highest yearly monthly mean, not an hourly extreme.
Kerama Islands in January
Typical January water temperature near Kerama Islands is 22.3°C (72.1°F), with yearly monthly means from 21.8–23.0°C.
Kerama Islands in February
Typical February water temperature near Kerama Islands is 21.9°C (71.4°F), with yearly monthly means from 21.2–22.6°C.
Kerama Islands in March
Typical March water temperature near Kerama Islands is 21.8°C (71.2°F), with yearly monthly means from 21.5–22.0°C.
Kerama Islands in April
Typical April water temperature near Kerama Islands is 22.9°C (73.2°F), with yearly monthly means from 22.2–23.4°C.
Kerama Islands in May
Typical May water temperature near Kerama Islands is 24.4°C (75.9°F), with yearly monthly means from 23.8–24.7°C.
Kerama Islands in June
Typical June water temperature near Kerama Islands is 27.1°C (80.8°F), with yearly monthly means from 26.3–27.9°C.
Kerama Islands in July
Typical July water temperature near Kerama Islands is 29.3°C (84.7°F), with yearly monthly means from 28.9–30.0°C.
Kerama Islands in August
Typical August water temperature near Kerama Islands is 29.5°C (85.1°F), with yearly monthly means from 28.4–30.5°C.
Kerama Islands in September
Typical September water temperature near Kerama Islands is 29.8°C (85.6°F), with yearly monthly means from 29.4–30.1°C.
Kerama Islands in October
Typical October water temperature near Kerama Islands is 28.6°C (83.5°F), with yearly monthly means from 27.8–29.5°C.
Kerama Islands in November
Typical November water temperature near Kerama Islands is 26.5°C (79.7°F), with yearly monthly means from 25.8–26.8°C.
Kerama Islands in December
Typical December water temperature near Kerama Islands is 24.2°C (75.6°F), with yearly monthly means from 24.2–24.3°C.
Forecast archive (growing)
These values come from hourly forecasts SnorkelForecast has stored. They cover only months with records and do not replace the historical baseline.
| Month | Min | Average | Max |
|---|---|---|---|
| June | 24.9°C / 76.8°F | 25.9°C / 78.6°F | 27.5°C / 81.5°F |
| July | 26.5°C / 79.7°F | 28.3°C / 83.0°F | 30.8°C / 87.4°F |
| August | 26.7°C / 80.1°F | 28.6°C / 83.4°F | 31.1°C / 88.0°F |
| September | 28.3°C / 82.9°F | 29.0°C / 84.2°F | 29.7°C / 85.5°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2734 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Kerama Islands
Okinawan islands with 'Kerama blue' water, turtles and bright coral.
- Area
- Okinawa
Kerama Islands Water Temperature: Common Questions
What is the water temperature in Kerama Islands today?
The current sea surface temperature near Kerama Islands is 29.0°C (84.2°F). Over the last 30 days, the average has been 28.8°C.
When is the water warmest in Kerama Islands?
The water is typically warmest in September, at around 29.8°C (85.6°F) in the 2023–2025 historical baseline.
When is the water coldest in Kerama Islands?
The water is typically coldest in March, at around 21.8°C (71.2°F) in the same historical baseline.
Can you swim in Kerama Islands today?
At 29.0°C, the water is usually comfortable for swimming and snorkeling.
Full Snorkeling Forecast
See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Kerama Islands.
View Snorkel Forecast →