Joint media release: New long-range marine heatwave forecasts now online

Senator The Hon Murray Watt, Minister for the Environment and Water
The Hon Julie Collins MP, Minister for Agriculture, Fisheries and Forestry

Australians are now able access free long-range marine heatwave (MHW) forecasts, to help better prepare for ocean temperature extremes that can impact habitats, threatened species, fisheries, marine parks, and other ocean activities.

The forecasts, now available on the Bureau of Meteorology website will provide information about the likelihood, location and predicted severity of marine heatwaves around Australia up to 4 months ahead.

Periods of sustained extreme ocean temperatures pose serious risks to fisheries, aquaculture, coral reefs, protected species and marine ecosystems. These events can disrupt industries, communities and cultural activities that depend on healthy oceans. 

By providing advance notice of marine heatwave conditions, these forecasts will allow marine users and governments to better prepare, adapt operations, plan surveys and brief others. It will also help to inform research into the impacts of warming on our ocean and future adaptation plans for marine environments.

Australia’s ocean was the warmest on record in 2024–25, with widespread marine heatwaves. A marine heatwave is a period of sustained extreme ocean temperatures, when ocean temperatures in a location are warmer than usual for the time of year for a defined period. 

Minister for the Environment and Water, Murray Watt said greater forecasting will help Australia to prepare for water temperature events in the future.

“Marine heatwaves were listed as a key hazard in the National Climate Assessment, and we expect them to become more common due to climate change,” Minister Watt said. 

"Recent extreme marine heatwave events have had serious impacts on ocean health, protected species, and fisheries and aquaculture operations in Australian waters, including mass fish kills, low fishery yields, and contributing to algal blooms.

“These outlooks will step beyond monitoring and will aim to forecast potential issues before they eventuate.”

Minister for Agriculture, Fisheries and Forestry, Julie Collins said industry would particularly benefit.

“This information will be made publicly available so that the fishing and aquaculture industry can make informed decisions about their operations or their catch, based on what conditions may look like later in the season,” Minister Collins said.

“This is not only important for long-term business viability, but also impacts Australia’s food security and the national economy.”

The long-range marine heatwave work is a research collaboration between the Bureau of Meteorology and Australia’s national science agency CSIRO. It is funded by the Department of Climate Change, Energy, the Environment and Water, the Fisheries Research and Development Corporation (FRDC) and CSIRO.

The forecast will be updated 3 times weekly and presented in 2 new sets of regional maps, showing the probability of a marine heatwave occurring and the category of marine heatwave (none, moderate, strong, severe or extreme).

The categories are a useful and intuitive way to communicate extreme ocean temperatures.

The new marine heatwave forecast information can be found on the Bureau’s Long-range ocean forecasts pages. Navigate to the marine heatwave forecast from the homepage on bom.gov.au by clicking on the ''Weather and climate' drop-down menu, then under 'Specialised forecasts and observations' go to 'Coasts and oceans'.