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.
Sheep producers across WA have been urged to monitor signs of increased worm burden in their flocks, following unseasonal downpours across large parts of the state earlier this month.
Adelaide's rainy run that has spanned the last five seasons may come to an end in autumn.
The southeast corner of Queensland will enter autumn longing for rain and cooler temperatures after enduring its hottest summer on record.