Napili Bay Water Temperature
Updated Wed 05:23 (Pacific/Honolulu)
USA · Forecast updated Sep 23, 2026, 05:23 UTC
Current Sea Temperature
27.7°C
81.9°F
Warm water
Valid Sep 23, 2026, 05:23 (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 27.2°C (81.0°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 27.7°C, versus 27.6°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 Napili Bay, typical monthly averages range from about 24.6°C (76.3°F) in February to 27.2°C (81.0°F) in September.
Over the past 30 days, the average sea temperature in Napili Bay has been 27.5°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Napili Bay, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 25.0–25.6°C | 25.3°C / 77.5°F |
| February | 24.5–24.7°C | 24.6°C / 76.3°F |
| March | 24.1–25.2°C | 24.7°C / 76.5°F |
| April | 24.5–25.7°C | 25.2°C / 77.4°F |
| May | 25.3–25.9°C | 25.6°C / 78.1°F |
| June | 26.0–26.6°C | 26.2°C / 79.2°F |
| July | 26.3–26.8°C | 26.6°C / 79.9°F |
| August | 26.8–27.4°C | 27.0°C / 80.6°F |
| September | 26.9–27.6°C | 27.2°C / 81.0°F |
| October | 26.5–27.4°C | 27.0°C / 80.6°F |
| November | 26.2–26.5°C | 26.4°C / 79.5°F |
| December | 25.6–26.0°C | 25.8°C / 78.4°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (21.04, -156.71). 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.
Napili Bay in January
Typical January water temperature near Napili Bay is 25.3°C (77.5°F), with yearly monthly means from 25.0–25.6°C.
Napili Bay in February
Typical February water temperature near Napili Bay is 24.6°C (76.3°F), with yearly monthly means from 24.5–24.7°C.
Napili Bay in March
Typical March water temperature near Napili Bay is 24.7°C (76.5°F), with yearly monthly means from 24.1–25.2°C.
Napili Bay in April
Typical April water temperature near Napili Bay is 25.2°C (77.4°F), with yearly monthly means from 24.5–25.7°C.
Napili Bay in May
Typical May water temperature near Napili Bay is 25.6°C (78.1°F), with yearly monthly means from 25.3–25.9°C.
Napili Bay in June
Typical June water temperature near Napili Bay is 26.2°C (79.2°F), with yearly monthly means from 26.0–26.6°C.
Napili Bay in July
Typical July water temperature near Napili Bay is 26.6°C (79.9°F), with yearly monthly means from 26.3–26.8°C.
Napili Bay in August
Typical August water temperature near Napili Bay is 27.0°C (80.6°F), with yearly monthly means from 26.8–27.4°C.
Napili Bay in September
Typical September water temperature near Napili Bay is 27.2°C (81.0°F), with yearly monthly means from 26.9–27.6°C.
Napili Bay in October
Typical October water temperature near Napili Bay is 27.0°C (80.6°F), with yearly monthly means from 26.5–27.4°C.
Napili Bay in November
Typical November water temperature near Napili Bay is 26.4°C (79.5°F), with yearly monthly means from 26.2–26.5°C.
Napili Bay in December
Typical December water temperature near Napili Bay is 25.8°C (78.4°F), with yearly monthly means from 25.6–26.0°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 | 25.9°C / 78.6°F | 26.5°C / 79.6°F | 27.3°C / 81.1°F |
| July | 26.1°C / 79.0°F | 26.8°C / 80.2°F | 27.4°C / 81.3°F |
| August | 26.1°C / 79.0°F | 27.1°C / 80.7°F | 28.0°C / 82.4°F |
| September | 27.0°C / 80.6°F | 27.6°C / 81.6°F | 28.1°C / 82.6°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2749 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Napili Bay
A gentle crescent bay on West Maui, Napili is a beginner-friendly snorkeling spot with green sea turtles and reef along both points. Calmest in the early morning and during lighter summer swells.
- Area
- Maui, Hawaii
Napili Bay Water Temperature: Common Questions
What is the water temperature in Napili Bay today?
The current sea surface temperature near Napili Bay is 27.7°C (81.9°F). Over the last 30 days, the average has been 27.5°C.
When is the water warmest in Napili Bay?
The water is typically warmest in September, at around 27.2°C (81.0°F) in the 2023–2025 historical baseline.
When is the water coldest in Napili Bay?
The water is typically coldest in February, at around 24.6°C (76.3°F) in the same historical baseline.
Can you swim in Napili Bay today?
At 27.7°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 Napili Bay.
View Snorkel Forecast →