NINO3.4 Index

The NINO3.4 index is one of several El Niño/Southern Oscillation (ENSO) indicators based on sea surface temperatures.

NINO3.4 is the average sea surface temperature anomaly in the region bounded by 5°N to 5°S, from 170°W to 120°W. This region has large variability on El Niño time scales, and is close to the region where changes in local sea-surface temperature are important for shifting the large region of rainfall typically located in the far western Pacific.

An El Niño or La Niña event is identified if the 5-month running-average of the NINO3.4 index exceeds +0.4°C for El Niño or -0.4°C for La Niña for at least 6 consecutive months.

• 10:31 AEDT Spectacular spiral low and outback storms
• 14:01 AEDT Severe heatwave takes hold of NSW
• 12:53 AEDT Heaviest rain in almost three years in Victorian city
• 11:34 AEDT Big stormy end to spring looms for Australia