Ocean temperature extremes occur at different scales, from local events in the coastal ocean to large and longer events further offshore. Their characteristics and driving processes vary with a major influence of wind stress on the continental shelf, compared to mesoscale dynamics in the open ocean. We investigate the different drivers and trends of extreme cold and warm anomalies in the Tasman Sea, focusing on the ocean response at depth. We show that regular marine heatwaves extend down to hundreds of meters, not restricted to the surface mixed layer and its seasonal variability. The mixed layer depth however controls the maximum warm anomalies, which are particularly enhanced in the Tasman front due to strong lateral gradients. This study is purely observational, based on IMOS in situ mooring and ARGO dataset.