The South Pacific Convergence Zone (SPCZ) is a band of low-level convergence, cloudiness and precipitation extending from the west Pacific warm pool south-eastwards towards French Polynesia. It shares some characteristics with the Intertropical Convergence Zone (ITCZ) which lies just north of the Equator, but is more extratropical in nature, especially east of the Dateline.

This zone occurs where the southeast trades from transitory anticyclones to the south meet with the semipermanent easterly flow from the eastern South Pacific anticyclone. The SPCZ exists in summer and winter, with approximately the same orientation and location. It is often distinct from the ITCZ over Australia, but at times they become one continuous zone of convergence.

The location of the SPCZ is affected by ENSO and Interdecadal Pacific Oscillation conditions. The South Pacific Convergence Zone moves northeast during El Niño and southwest during La Niña events. The same movement takes place during positive IPO and negative IPO phases respectively. West of about 140 W, both the SOI and IPO strongly influence the SPCZ latitude, but farther east only the SOI is a significant factor. Only near 170 W is there any indication of an interaction between the two factors. (Folland et al, 2002)

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