Month-specific sea-surface temperature · USA
Oahu Sea Temperature in July
27.0°C
80.6°F
In July, sea-surface temperature near Oahu has a historical monthly average of 27.0°C. This is not the reading for any particular holiday date.
Across 2022–2025, the lowest and highest yearly July monthly means were 26.9–27.1°C. These are not daily extremes.
Previous month
June · 26.6°C
Change into July: +0.4°C
Next month
August · 27.4°C
Change into next month: +0.4°C
Can you swim or snorkel in Oahu in July?
At 27.0°C our temperature-only guide describes the water as warm 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?
Most people are comfortable in swimwear or a light rash guard.
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 July. Check again close to your trip.
Waves and wind: recorded-model conditions for July
These figures come from a separately modelled, date-specific wind/wave backfill, not the NOAA SST series. A single observed season is not a climatological likelihood or a guarantee of safe conditions.
Morning calm hours
0%
Afternoon calm hours
0%
Historical coverage
July 2026
31 valid days
A “calm hour” meets fixed modelled wave/wind thresholds; neither visibility nor local currents, entry conditions or actual beach safety is measured here. Periods may differ by coast.
Data source and limitations
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2022–2025. Marine model grid near 21.44, -158.00. 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.