This study presents an updated diatom–conductivity model to reconstruct past Southern Hemisphere westerly wind strength from lake sediments on sub-Antarctic Macquarie Island. We analysed diatom–environment relationships using seasonal and multi-year water chemistry and isotope data. Diatoms respond strongly to changes in lake water conductivity driven by wind-blown sea spray. The model provides a reliable tool for tracking long-term wind patterns and understanding past and future climate change.