Southern Oscillation Index (SOI)

The Southern Oscillation Index (SOI) measures the difference in air pressure between Tahiti and Darwin, Australia. This pressure difference indicates the phase of the El Niño-Southern Oscillation (ENSO) climate pattern. A strongly negative SOI suggests El Niño conditions, often leading to warmer and drier weather in some regions, while a positive SOI indicates La Niña, associated with cooler and wetter conditions. The SOI helps meteorologists monitor and predict global climate variations, influencing weather-related decisions and preparedness worldwide.