Month-specific sea-surface temperature · Australia

Agincourt Reef Sea Temperature in December

29.1°C

84.4°F

In December, sea-surface temperature near Agincourt Reef has a historical monthly average of 29.1°C. This is not the reading for any particular holiday date.

Across 2023–2025, the lowest and highest yearly December monthly means were 28.4–29.6°C. These are not daily extremes.

Previous month

November · 27.8°C

Change into December: +1.3°C

Next month

January · 29.9°C

Change into next month: +0.8°C

Can you swim or snorkel in Agincourt Reef in December?

At 29.1°C our temperature-only guide describes the water as very warm 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?

Swimwear is usually enough; a rash guard adds sun protection.

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 December. Check again close to your trip.

Waves and wind: recorded-model conditions for December

These figures come from a separately modelled, date-specific wind/wave backfill, not the NOAA SST series. A single observed season is not a climatological likelihood or a guarantee of safe conditions.

Compare nearby coasts with their own evidence

Coast	Morning	Afternoon	Period
Great Barrier Reef	43%	46%	Dec 2025

A “calm hour” meets fixed modelled wave/wind thresholds; neither visibility nor local currents, entry conditions or actual beach safety is measured here. Periods may differ by coast.

Nearby places in December

Comparable historical averages from independent marine grid cells. Warmer water does not imply safe snorkeling.

Great Barrier Reef 29.0°C
Low Isles 29.5°C
Hastings Reef 29.0°C
Moore Reef 28.8°C
Michaelmas Cay 28.7°C
Port Douglas 29.6°C

Agincourt Reef Sea Temperature: All 12 Months

Choose a month for available historical evidence, month comparisons and swim guidance. Missing history is clearly marked and never presented as a long-term normal.

January 29.9°C February 29.5°C March 29.3°C April 28.6°C May 26.6°C June 25.6°C July 25.0°C August 24.6°C September 25.4°C October 26.4°C November 27.8°C December 29.1°C

Data source and limitations

Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near -16.04, 145.87. 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.