The South Pacific Convergence Zone (SPCZ), the dominant feature of the atmospheric circulation in the south west Pacific, varies its location on interannual to decadal timescales. Interannual variability is largely driven by the polarity of the El Nino/Southern Oscillation, whilst decadal variability occurs in phase with the Interdecadal Pacific Oscillation (IPO). As a result the SPCZ plays a pivotal role in both variability and trends in South Pacific climate. This variability modulates longer term warming trends observed in the region. These movements, and impacts on South Pacific climate are discussed.