Climate
KEY FINDINGS FROM OUR 2025 REPORT CARD
Except rainfall, there was nothing average about temperature and climate influences during the 2023 to 2024 reporting year, which included one cyclone and the fifth mass coral bleaching event since 2016 on the Great Barrier Reef.
Rainfall
Both the Ross and Black Basins received an average amount of rainfall over the 2023-2024 year.
Air temperature
If you were feeling a little hot in 2023-2024, you weren’t imagining it. Every month was warmer than the long-term average. The annual average air temperature was 24.9°C in the Ross Basin, that's warmer than the long-term norm by 1.2°C. The Black Basin’s average was 24.4°C, exceeding its long-term norm by 1.3°C.
Wind and storm surge
In January 2024, Severe Tropical Cyclone Kirrily peaked as a Category 3 system in the Coral Sea shortly before crossing the coastline about 50km northwest of Townsville, as a Category 1 tropical cyclone. Destructive winds and storm surge can damage marine and coastal habitats, with the severity of impact dependent upon how long areas are exposed and the intensity, as well as things like shape of the seafloor and presence of physical barriers.
Sea surface temperatures
We weren’t the only ones feeling the heat, so were corals. The annual average sea surface temperature was 26.8°C, which was 0.6°C above the long-term average. Sea surface temperatures in our reporting region were ‘above average’ to the ‘highest 1%’ on record for three-quarters of the year.
Prolonged exposure to heat can lead to coral bleaching. With most of the marine zone experiencing between 4 and 8+ Degree Heating Weeks, the risk of coral bleaching ranged from ‘low risk’ to ‘very high risk.’
The 2023-2024 summer saw the fifth mass coral bleaching event since 2016 occur across the Great Barrier Reef, affecting the northern, central and southern regions. The largest spatial footprint of coral bleaching yet recorded. The impacts to coral habitat may not be reflected in this year’s Report Card, as monitoring surveys were undertaken before the full impact of this event could be assessed.
