Updated Sat 14:41 (Pacific/Honolulu)
USA · Forecast updated Sep 26, 2026, 14:41 UTC
Current Sea Temperature
27.3°C
81.1°F
Warm water
Valid Sep 26, 2026, 14:41 (Pacific/Honolulu). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
0.3°C below
The typical September average is 27.6°C (81.7°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 27.9°C, versus 28.0°C in the prior seven days.
What to wear
Warm water
Most people are comfortable in swimwear or a light rash guard.
Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions or replace the snorkel forecast.
In the historical baseline for Oahu, typical monthly averages range from about 24.0°C (75.2°F) in February to 27.6°C (81.7°F) in September.
Over the past 30 days, the average sea temperature in Oahu has been 27.8°C.
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Oahu, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 24.6–25.3°C | 25.0°C / 77.0°F |
| February | 23.9–24.1°C | 24.0°C / 75.2°F |
| March | 23.9–25.5°C | 24.8°C / 76.6°F |
| April | 24.9–26.2°C | 25.7°C / 78.3°F |
| May | 26.0–26.4°C | 26.2°C / 79.2°F |
| June | 26.6–26.6°C | 26.6°C / 79.9°F |
| July | 26.9–27.1°C | 27.0°C / 80.6°F |
| August | 27.1–27.8°C | 27.4°C / 81.3°F |
| September | 27.4–27.7°C | 27.6°C / 81.7°F |
| October | 27.2–27.8°C | 27.5°C / 81.5°F |
| November | 25.7–26.4°C | 26.1°C / 79.0°F |
| December | 24.9–25.7°C | 25.4°C / 77.7°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (21.29, -158.04). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
Each month uses the 2023–2025 baseline. The range is the lowest and highest yearly monthly mean, not an hourly extreme.
Typical January water temperature near Oahu is 25.0°C (77.0°F), with yearly monthly means from 24.6–25.3°C.
Typical February water temperature near Oahu is 24.0°C (75.2°F), with yearly monthly means from 23.9–24.1°C.
Typical March water temperature near Oahu is 24.8°C (76.6°F), with yearly monthly means from 23.9–25.5°C.
Typical April water temperature near Oahu is 25.7°C (78.3°F), with yearly monthly means from 24.9–26.2°C.
Typical May water temperature near Oahu is 26.2°C (79.2°F), with yearly monthly means from 26.0–26.4°C.
Typical June water temperature near Oahu is 26.6°C (79.9°F), with yearly monthly means from 26.6–26.6°C.
Typical July water temperature near Oahu is 27.0°C (80.6°F), with yearly monthly means from 26.9–27.1°C.
Typical August water temperature near Oahu is 27.4°C (81.3°F), with yearly monthly means from 27.1–27.8°C.
Typical September water temperature near Oahu is 27.6°C (81.7°F), with yearly monthly means from 27.4–27.7°C.
Typical October water temperature near Oahu is 27.5°C (81.5°F), with yearly monthly means from 27.2–27.8°C.
Typical November water temperature near Oahu is 26.1°C (79.0°F), with yearly monthly means from 25.7–26.4°C.
Typical December water temperature near Oahu is 25.4°C (77.7°F), with yearly monthly means from 24.9–25.7°C.
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 | 27.2°C / 81.0°F | 27.4°C / 81.3°F | 27.6°C / 81.7°F |
| July | 26.8°C / 80.2°F | 27.5°C / 81.5°F | 28.4°C / 83.1°F |
| August | 27.4°C / 81.3°F | 27.9°C / 82.3°F | 28.5°C / 83.3°F |
| September | 26.3°C / 79.3°F | 27.7°C / 81.9°F | 28.4°C / 83.1°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2235 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
Oahu snorkel report hub for comparing protected bays, west-side reefs and seasonal shore exposure.
The current sea surface temperature near Oahu is 27.3°C (81.1°F). Over the last 30 days, the average has been 27.8°C.
The water is typically warmest in September, at around 27.6°C (81.7°F) in the 2023–2025 historical baseline.
The water is typically coldest in February, at around 24.0°C (75.2°F) in the same historical baseline.
At 27.3°C, the water is usually comfortable for swimming and snorkeling.
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See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Oahu.
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