Updated Thu 11:21 (Australia/Brisbane)
Australia · Forecast updated Sep 17, 2026, 11:21 UTC
Current Sea Temperature
23.8°C
74.8°F
Mild water
Valid Sep 17, 2026, 11:21 (Australia/Brisbane). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
0.9°C below
The typical September average is 24.7°C (76.5°F) from the historical baseline.
Recent trend
At least two weeks of records are needed before showing a reliable trend.
What to wear
Mild water
A rash guard is useful; cold-sensitive snorkelers may prefer a shorty wetsuit.
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 Great Barrier Reef, typical monthly averages range from about 23.6°C (74.5°F) in August to 29.9°C (85.8°F) in January.
Over the past 30 days, the average sea temperature in Great Barrier Reef has been 23.9°C.
Southern Hemisphere. Summer is generally December–February; winter is June–August.
Typical monthly sea-surface temperature near Great Barrier Reef, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 29.3–30.3°C | 29.9°C / 85.8°F |
| February | 29.0–30.1°C | 29.5°C / 85.1°F |
| March | 29.0–29.2°C | 29.1°C / 84.4°F |
| April | 27.8–28.9°C | 28.3°C / 82.9°F |
| May | 25.7–26.1°C | 25.9°C / 78.6°F |
| June | 24.4–24.9°C | 24.6°C / 76.3°F |
| July | 23.7–24.3°C | 24.0°C / 75.2°F |
| August | 23.3–24.1°C | 23.6°C / 74.5°F |
| September | 24.3–25.2°C | 24.7°C / 76.5°F |
| October | 25.7–26.8°C | 26.3°C / 79.3°F |
| November | 27.0–29.1°C | 28.0°C / 82.4°F |
| December | 28.3–29.7°C | 29.0°C / 84.2°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (-16.29, 145.71). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
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 Great Barrier Reef is 29.9°C (85.8°F), with yearly monthly means from 29.3–30.3°C.
Typical February water temperature near Great Barrier Reef is 29.5°C (85.1°F), with yearly monthly means from 29.0–30.1°C.
Typical March water temperature near Great Barrier Reef is 29.1°C (84.4°F), with yearly monthly means from 29.0–29.2°C.
Typical April water temperature near Great Barrier Reef is 28.3°C (82.9°F), with yearly monthly means from 27.8–28.9°C.
Typical May water temperature near Great Barrier Reef is 25.9°C (78.6°F), with yearly monthly means from 25.7–26.1°C.
Typical June water temperature near Great Barrier Reef is 24.6°C (76.3°F), with yearly monthly means from 24.4–24.9°C.
Typical July water temperature near Great Barrier Reef is 24.0°C (75.2°F), with yearly monthly means from 23.7–24.3°C.
Typical August water temperature near Great Barrier Reef is 23.6°C (74.5°F), with yearly monthly means from 23.3–24.1°C.
Typical September water temperature near Great Barrier Reef is 24.7°C (76.5°F), with yearly monthly means from 24.3–25.2°C.
Typical October water temperature near Great Barrier Reef is 26.3°C (79.3°F), with yearly monthly means from 25.7–26.8°C.
Typical November water temperature near Great Barrier Reef is 28.0°C (82.4°F), with yearly monthly means from 27.0–29.1°C.
Typical December water temperature near Great Barrier Reef is 29.0°C (84.2°F), with yearly monthly means from 28.3–29.7°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 |
|---|---|---|---|
| September | 23.4°C / 74.1°F | 23.6°C / 74.5°F | 23.9°C / 75.0°F |
Partial coverage: 1 calendar months with records. Profile calculated from 74 hourly forecast records across 1 monthly periods. This is a growing archive, not a long-term climate normal.
Great Barrier Reef snorkel hub for comparing Cairns, Port Douglas and island/outer-reef forecasts before choosing a trip.
The current sea surface temperature near Great Barrier Reef is 23.8°C (74.8°F). Over the last 30 days, the average has been 23.9°C.
The water is typically warmest in January, at around 29.9°C (85.8°F) in the 2023–2025 historical baseline.
The water is typically coldest in August, at around 23.6°C (74.5°F) in the same historical baseline.
At 23.8°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 Great Barrier Reef.
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