Above average ocean temperatures leading to marine heatwaves have implications for many marine ecosystems and industries. The impacts felt include mass coral bleaching and mortality, altered aquaculture yields and changes in wild fish migration patterns. Seasonal forecasts of marine heatwave risk from dynamical ocean-atmosphere models can be very useful tools for marine managers, businesses and researchers. The Australian Bureau of Meteorology’s seasonal forecast model ACCESS-S2 currently produces operational real-time forecasts of sea surface temperatures. Experimental products based on marine heatwave metrics using daily forecasts and probabilities of exceeding the 90th percentile are currently being developed and assessed. These new products will complement existing operational accumulated thermal stress forecast products developed for coral bleaching to improve both the understanding and the management of these events, as well as the complex interactions that lead to them, particularly in a changing climate.