April 2024

Southern Oscillation Index (SOI)

  • The 30-day Southern Oscillation Index (SOI) for the 30 days to 28 April 2024 was -8.5 (Figure 23). The 90-day SOI value was -7.3.
  • Sustained negative values of the SOI below −7 typically indicate El Niño while sustained positive values above +7 typically indicate La Niña.
Latest 30-day moving SOI
Sourced from the Australian Bureau of Meteorology
Image for Southern Oscillation Index