Marine heatwaves (MHWs) have emerged as one of the most significant manifestations of ocean warming around Australia, affecting marine ecosystems, fisheries, and coastal communities. This poster presents a monthly visualisation of MHW conditions across Australian waters from 1982 to 2025, providing a continuous record of the spatial extent, intensity, and evolution of extreme ocean temperature events over more than four decades. Using satellite-derived sea surface temperature observations and standard MHW detection methods, the animation highlights both regional and continental-scale variability, revealing trends in the frequency, duration, and severity of MHWs. The record captures well-known events, including the 2011 Western Australian marine heatwave and recent widespread extremes, while illustrating the increasing prominence of MHWs across Australia's marine estate. This long-term perspective provides an accessible tool for communicating climate-driven ocean change and supports ongoing research, monitoring, and adaptation efforts in Australia's marine environment.