Hanauma Bay Sea Temperature
Updated Sat 17:14 (Pacific/Honolulu)
USA · Forecast updated Sep 5, 2026, 17:14 UTC
Current Sea Temperature
26.7°C
80.1°F
Warm water
Versus this month's average
Close to average
The September average in our archive is 26.8°C (80.2°F).
Recent trend
Holding fairly steady
Seven-day average: 26.7°C, versus 26.7°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.
Sea Surface Temperature Over the Year
In the data collected for Hanauma Bay, monthly averages range from about 26.1°C (79.0°F) in June to 26.8°C (80.2°F) in September.
Over the past 30 days, the average sea temperature in Hanauma Bay has been 26.6°C.
Monthly Water Temperature Averages
Northern Hemisphere. Summer is generally June–August; winter is December–February.
| Month | Min | Average | Max |
|---|---|---|---|
| June | 25.4°C / 77.7°F | 26.1°C / 79.0°F | 27.4°C / 81.3°F |
| July | 25.9°C / 78.6°F | 26.4°C / 79.6°F | 28.0°C / 82.4°F |
| August | 25.9°C / 78.6°F | 26.7°C / 80.0°F | 27.6°C / 81.7°F |
| September | 26.5°C / 79.7°F | 26.8°C / 80.2°F | 27.0°C / 80.6°F |
Profile calculated from 2330 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Hanauma Bay
A protected marine life conservation area inside a volcanic cone on Oahu, Hanauma Bay is Hawaii's most popular snorkeling spot. The shallow inner reef stays calm in most conditions; aim for an early slot when water is clearest and crowds are thinnest.
- Area
- Oahu, Hawaii
Hanauma Bay Water Temperature: Common Questions
What is the sea temperature in Hanauma Bay today?
The current sea surface temperature in Hanauma Bay is 26.7°C. Over the last 30 days, the average has been 26.6°C.
When is the water warmest in Hanauma Bay?
The warmest monthly average in the Hanauma Bay archive is September, at around 26.8°C (80.2°F).
When is the water coldest in Hanauma Bay?
The coldest monthly average in the archive is June, at around 26.1°C (79.0°F).
Can you swim in Hanauma Bay today?
At 26.7°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 Hanauma Bay.
View Snorkel Forecast →