Ulua Mokapu Water Temperature
Updated Sat 14:41 (Pacific/Honolulu)
USA · Forecast updated Sep 26, 2026, 14:41 UTC
Current Sea Temperature
27.9°C
82.2°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
0.5°C above
The typical September average is 27.4°C (81.3°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 28.0°C, versus 27.9°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.
Typical Sea Temperature Over the Year
In the historical baseline for Ulua Mokapu, typical monthly averages range from about 24.8°C (76.6°F) in February to 27.4°C (81.3°F) in September.
Over the past 30 days, the average sea temperature in Ulua Mokapu has been 27.9°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Ulua Mokapu, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 25.3–25.5°C | 25.4°C / 77.7°F |
| February | 24.7–24.9°C | 24.8°C / 76.6°F |
| March | 24.5–25.2°C | 25.0°C / 77.0°F |
| April | 24.8–25.6°C | 25.3°C / 77.5°F |
| May | 25.8–26.2°C | 26.0°C / 78.8°F |
| June | 26.3–26.9°C | 26.5°C / 79.7°F |
| July | 26.4–27.1°C | 26.8°C / 80.2°F |
| August | 27.1–27.5°C | 27.3°C / 81.1°F |
| September | 27.1–27.8°C | 27.4°C / 81.3°F |
| October | 26.9–27.5°C | 27.2°C / 81.0°F |
| November | 26.5–26.7°C | 26.6°C / 79.9°F |
| December | 25.7–26.1°C | 25.9°C / 78.6°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (20.71, -156.46). 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.
Ulua Mokapu in January
Typical January water temperature near Ulua Mokapu is 25.4°C (77.7°F), with yearly monthly means from 25.3–25.5°C.
Ulua Mokapu in February
Typical February water temperature near Ulua Mokapu is 24.8°C (76.6°F), with yearly monthly means from 24.7–24.9°C.
Ulua Mokapu in March
Typical March water temperature near Ulua Mokapu is 25.0°C (77.0°F), with yearly monthly means from 24.5–25.2°C.
Ulua Mokapu in April
Typical April water temperature near Ulua Mokapu is 25.3°C (77.5°F), with yearly monthly means from 24.8–25.6°C.
Ulua Mokapu in May
Typical May water temperature near Ulua Mokapu is 26.0°C (78.8°F), with yearly monthly means from 25.8–26.2°C.
Ulua Mokapu in June
Typical June water temperature near Ulua Mokapu is 26.5°C (79.7°F), with yearly monthly means from 26.3–26.9°C.
Ulua Mokapu in July
Typical July water temperature near Ulua Mokapu is 26.8°C (80.2°F), with yearly monthly means from 26.4–27.1°C.
Ulua Mokapu in August
Typical August water temperature near Ulua Mokapu is 27.3°C (81.1°F), with yearly monthly means from 27.1–27.5°C.
Ulua Mokapu in September
Typical September water temperature near Ulua Mokapu is 27.4°C (81.3°F), with yearly monthly means from 27.1–27.8°C.
Ulua Mokapu in October
Typical October water temperature near Ulua Mokapu is 27.2°C (81.0°F), with yearly monthly means from 26.9–27.5°C.
Ulua Mokapu in November
Typical November water temperature near Ulua Mokapu is 26.6°C (79.9°F), with yearly monthly means from 26.5–26.7°C.
Ulua Mokapu in December
Typical December water temperature near Ulua Mokapu is 25.9°C (78.6°F), with yearly monthly means from 25.7–26.1°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 | 26.8°C / 80.2°F | 27.2°C / 80.9°F | 27.6°C / 81.7°F |
| July | 26.7°C / 80.1°F | 27.3°C / 81.1°F | 27.8°C / 82.0°F |
| August | 26.9°C / 80.4°F | 27.6°C / 81.7°F | 28.4°C / 83.1°F |
| September | 27.4°C / 81.3°F | 27.9°C / 82.2°F | 28.5°C / 83.3°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2236 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Ulua Mokapu
Ulua and Mokapu are adjacent South Maui reef beaches with easy entries, coral shelves and frequent turtles. They are usually best early in the morning before trade winds roughen the surface.
- Area
- Maui, Hawaii
Ulua Mokapu Water Temperature: Common Questions
What is the water temperature in Ulua Mokapu today?
The current sea surface temperature near Ulua Mokapu is 27.9°C (82.2°F). Over the last 30 days, the average has been 27.9°C.
When is the water warmest in Ulua Mokapu?
The water is typically warmest in September, at around 27.4°C (81.3°F) in the 2023–2025 historical baseline.
When is the water coldest in Ulua Mokapu?
The water is typically coldest in February, at around 24.8°C (76.6°F) in the same historical baseline.
Can you swim in Ulua Mokapu today?
At 27.9°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 Ulua Mokapu.
View Snorkel Forecast →