The NINO3.4 index is one of several El Niņo/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 Niņo 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 Niņo or La Niņa event is identified if the 5-month running-average of the NINO3.4 index exceeds +0.4°C for El Niņo or -0.4°C for La Niņa for at least 6 consecutive months.
Wrapping up a hot and humid summer many will be happy to forget, rain is on its way for most of NSW east of the divide.
Although autumn is on the way, the Bureau of Meteorology has warned the hot weather is likely to continue, with warmer than average temperatures forecast for most of southern and eastern Australia.
Residents in Queensland's Gulf country are criticising the State Government's strict flooded road closure policy.