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.
Backyards in Queanbeyan and parts of Canberra have been covered with "golf-ball sized" hailstones and the roof of a supermarket has partially collapsed after a storm hit the region.
A western Queensland church has raised more than $90,000 for a scheme to keep rural contractors in work during the ongoing drought.
Much of southeastern Australia is experiencing its sunniest week since spring and skies have been staying clear at night, effectively giving planet gazers a fine-tuned view of a rare feature.