Bay of Islands Water Temperature
Updated Sat 13:17 (Pacific/Auckland)
New Zealand · Forecast updated Sep 26, 2026, 13:17 UTC
Current Sea Temperature
15.8°C
60.4°F
Cold water
Valid Sep 26, 2026, 13:17 (Pacific/Auckland). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
Close to average
The typical September average is 15.6°C (60.1°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 15.7°C, versus 15.9°C in the prior seven days.
What to wear
Cold water
Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
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 Bay of Islands, typical monthly averages range from about 15.3°C (59.5°F) in August to 21.8°C (71.2°F) in February.
Over the past 30 days, the average sea temperature in Bay of Islands has been 15.9°C.
Historical baseline (full year)
Southern Hemisphere. Summer is generally December–February; winter is June–August.
Typical monthly sea-surface temperature near Bay of Islands, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 20.5–21.5°C | 20.9°C / 69.6°F |
| February | 21.7–22.0°C | 21.8°C / 71.2°F |
| March | 20.1–21.9°C | 21.2°C / 70.2°F |
| April | 19.6–20.4°C | 20.0°C / 68.0°F |
| May | 18.2–19.5°C | 18.7°C / 65.7°F |
| June | 16.7–17.1°C | 16.9°C / 62.4°F |
| July | 15.7–15.8°C | 15.8°C / 60.4°F |
| August | 14.9–15.6°C | 15.3°C / 59.5°F |
| September | 15.2–16.0°C | 15.6°C / 60.1°F |
| October | 15.8–15.8°C | 15.8°C / 60.4°F |
| November | 17.4–18.4°C | 17.7°C / 63.9°F |
| December | 19.0–19.7°C | 19.3°C / 66.7°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (-35.13, 174.21). 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.
Bay of Islands in January
Typical January water temperature near Bay of Islands is 20.9°C (69.6°F), with yearly monthly means from 20.5–21.5°C.
Bay of Islands in February
Typical February water temperature near Bay of Islands is 21.8°C (71.2°F), with yearly monthly means from 21.7–22.0°C.
Bay of Islands in March
Typical March water temperature near Bay of Islands is 21.2°C (70.2°F), with yearly monthly means from 20.1–21.9°C.
Bay of Islands in April
Typical April water temperature near Bay of Islands is 20.0°C (68.0°F), with yearly monthly means from 19.6–20.4°C.
Bay of Islands in May
Typical May water temperature near Bay of Islands is 18.7°C (65.7°F), with yearly monthly means from 18.2–19.5°C.
Bay of Islands in June
Typical June water temperature near Bay of Islands is 16.9°C (62.4°F), with yearly monthly means from 16.7–17.1°C.
Bay of Islands in July
Typical July water temperature near Bay of Islands is 15.8°C (60.4°F), with yearly monthly means from 15.7–15.8°C.
Bay of Islands in August
Typical August water temperature near Bay of Islands is 15.3°C (59.5°F), with yearly monthly means from 14.9–15.6°C.
Bay of Islands in September
Typical September water temperature near Bay of Islands is 15.6°C (60.1°F), with yearly monthly means from 15.2–16.0°C.
Bay of Islands in October
Typical October water temperature near Bay of Islands is 15.8°C (60.4°F), with yearly monthly means from 15.8–15.8°C.
Bay of Islands in November
Typical November water temperature near Bay of Islands is 17.7°C (63.9°F), with yearly monthly means from 17.4–18.4°C.
Bay of Islands in December
Typical December water temperature near Bay of Islands is 19.3°C (66.7°F), with yearly monthly means from 19.0–19.7°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 |
|---|---|---|---|
| August | 15.9°C / 60.6°F | 16.1°C / 61.1°F | 16.4°C / 61.5°F |
| September | 15.5°C / 59.9°F | 15.8°C / 60.5°F | 16.2°C / 61.2°F |
Partial coverage: 2 calendar months with records. Profile calculated from 1174 hourly forecast records across 2 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Bay of Islands
Subtropical Northland bays with clear water, kelp forests and abundant fish.
- Area
- Northland
Bay of Islands Water Temperature: Common Questions
What is the water temperature in Bay of Islands today?
The current sea surface temperature near Bay of Islands is 15.8°C (60.4°F). Over the last 30 days, the average has been 15.9°C.
When is the water warmest in Bay of Islands?
The water is typically warmest in February, at around 21.8°C (71.2°F) in the 2023–2025 historical baseline.
When is the water coldest in Bay of Islands?
The water is typically coldest in August, at around 15.3°C (59.5°F) in the same historical baseline. A wetsuit is usually recommended during this period.
Can you swim in Bay of Islands today?
At 15.8°C the water is cold. A thick wetsuit is strongly recommended.
Full Snorkeling Forecast
See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Bay of Islands.
View Snorkel Forecast →