Here we submitted modern core top radiolarian assemblage dataset in the Northwestern Australian Margin. The sample were collected during the German Sonne R/V Expedition SO 257. The dataset served as a calibration dataset to estimate past Summer Sea Surface Temperature (SST) of the Past using radiolarian species. We also submit herein IODP 363 Site U1483 (the Timor Sea), radiolarian assemblage data from the time interval between 500 and 1600 ka to discuss the impact of the Mid Pleistocene Transition on regional climate/ocean system such as the Indonesian Throughflow and the Australian Monsoon. For do so, we estimate the summer SST between 500 and 1600 ka relying on the SO 257 core top radiolarian assemblages.