The Bureau has launched new marine heatwave forecasts on the Long-range ocean forecasts pages of our website.
These forecasts show the likelihood, location and predicted severity of marine heatwaves in the Australian region up to 4 months ahead.
A marine heatwave is a period of unusually high ocean temperatures for a defined time and place. These extreme conditions can harm marine ecosystems and affect fisheries and aquaculture.
To help manage these risks, the forecasts were developed with support from the Australian Government Department of Climate Change, Energy, the Environment and Water (DCCEEW), the Fisheries Research and Development Corporation (FRDC) and CSIRO.
The launch of the new marine heatwave forecast service was today announced by the Minister for Environment and Water and the Minister for Agriculture, Fisheries and Forestry (Joint media release: New long-range marine heatwave forecasts now online | Ministers).
The forecasts build on 4 years of research using the Bureau’s ACCESS-S2 seasonal prediction system and have been tested with industry through national marine climate briefings and stakeholder engagement.
Recent summers have highlighted the urgency of this work. Australia’s oceans were the warmest on record in 2024–25, with widespread marine heatwaves causing coral bleaching on the east and west coasts, fish kills in Western Australia, and harmful algal blooms in South Australia.
Our engagement with decision-makers across fisheries and state agencies has shown us that marine heatwave categories are a useful and intuitive way to communicate extreme ocean temperatures.
Why it matters
Healthy oceans underpin Australia’s economy, food security and cultural heritage. With marine heatwaves becoming more frequent and severe under climate change, these forecasts give industries and communities the chance to act – protecting livelihoods, ecosystems and our marine species.
Marine heatwaves are a high priority in the Australian Government's Draft Sustainable Ocean Plan, and are considered a key hazard in the National Climate Risk Assessment.
Marine heatwave information is now a critical component for state-based marine heatwave response plans.
This capability represents a major step forward in supporting resilience for Australia’s marine industries and ecosystems in a warming climate.
The new marine heatwave forecast maps are updated 3 times weekly on the Bureau's website.