Month-specific sea-surface temperature · Japan
Kerama Islands Sea Temperature in May
24.4°C
75.9°F
In May, sea-surface temperature near Kerama Islands has a historical monthly average of 24.4°C. This is not the reading for any particular holiday date.
Across 2023–2025, the lowest and highest yearly May monthly means were 23.8–24.7°C. These are not daily extremes.
Previous month
April · 22.9°C
Change into May: +1.5°C
Next month
June · 27.1°C
Change into next month: +2.7°C
Can you swim or snorkel in Kerama Islands in May?
At 24.4°C our temperature-only guide describes the water as mild water. Comfort depends on your cold tolerance, immersion time and wind. A historical average cannot determine whether conditions are safe on any given day.
Do you need a wetsuit?
A rash guard is useful; cold-sensitive snorkelers may prefer a shorty wetsuit.
Which beach should you choose?
Look for a beach sheltered from the actual forecast waves and wind on your visit. Exposure, currents and entry conditions vary even where water temperatures are similar. Follow local warnings.
Check the current waves, wind and snorkeling forecast →
A live forecast does not predict a future May. Check again close to your trip.
Nearby places in May
Comparable historical averages from independent marine grid cells. Warmer water does not imply safe snorkeling.
- Okinawa - Blue Cave 24.3°C
Data source and limitations
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near 26.19, 127.35. Based on 3 yearly monthly means and 2232 recorded samples. Source methodology.
Modelled sea-surface temperatures do not establish underwater visibility, wildlife, calm currents or safe entry.