Month-specific sea-surface temperature · Australia
Green Island Sea Temperature in September
24.6°C
76.3°F
In September, sea-surface temperature near Green Island has a historical monthly average of 24.6°C. This is not the reading for any particular holiday date.
Across 2023–2025, the lowest and highest yearly September monthly means were 24.2–25.0°C. These are not daily extremes.
Previous month
August · 23.5°C
Change into September: +1.1°C
Next month
October · 26.3°C
Change into next month: +1.7°C
Can you swim or snorkel in Green Island in September?
At 24.6°C our temperature-only guide describes the water as mild water. Comfort depends on your cold tolerance, immersion time and wind. A historical average cannot determine whether conditions are safe on any given day.
Do you need a wetsuit?
A rash guard is useful; cold-sensitive snorkelers may prefer a shorty wetsuit.
Which beach should you choose?
Look for a beach sheltered from the actual forecast waves and wind on your visit. Exposure, currents and entry conditions vary even where water temperatures are similar. Follow local warnings.
Check the current waves, wind and snorkeling forecast →
A live forecast does not predict a future September. Check again close to your trip.
Nearby places in September
Comparable historical averages from independent marine grid cells. Warmer water does not imply safe snorkeling.
- Arlington Reef 24.8°C
- Michaelmas Cay 24.7°C
- Fitzroy Island 24.7°C
- Hastings Reef 25.1°C
- Cairns 24.8°C
- Moore Reef 25.2°C
Data source and limitations
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near -16.76, 145.97. Based on 3 yearly monthly means and 2160 recorded samples. Source methodology.
Modelled sea-surface temperatures do not establish underwater visibility, wildlife, calm currents or safe entry.