Month-specific sea-surface temperature · Australia
Cairns Sea Temperature in July
23.9°C
75.0°F
In July, sea-surface temperature near Cairns has a historical monthly average of 23.9°C. This is not the reading for any particular holiday date.
Across 2023–2025, the lowest and highest yearly July monthly means were 23.7–24.1°C. These are not daily extremes.
Previous month
June · 24.3°C
Change into July: -0.4°C
Next month
August · 23.6°C
Change into next month: -0.3°C
Can you swim or snorkel in Cairns in July?
At 23.9°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.
Cairns is a mainland gateway. Reef water a short boat ride east can differ from Trinity Inlet. Use the monthly profile as a regional guide, then check Green Island, Fitzroy Island or an outer-reef forecast for the water you will enter.
Check the current waves, wind and snorkeling forecast →
A live forecast does not predict a future July. Check again close to your trip.
Nearby places in July
Comparable historical averages from independent marine grid cells. Warmer water does not imply safe snorkeling.
- Fitzroy Island 24.0°C
- Green Island 23.9°C
- Arlington Reef 24.0°C
- Michaelmas Cay 24.0°C
- Hastings Reef 24.3°C
- Moore Reef 24.8°C
Data source and limitations
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near -16.92, 145.77. Based on 3 yearly monthly means and 2232 recorded samples. Source methodology.
Modelled sea-surface temperatures do not establish underwater visibility, wildlife, calm currents or safe entry.