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.
Witnesses saw a man being swept away after his vehicle went into floodwaters near Lismore in far north New South Wales, police say, as a heavy downpour and strong winds hit the state's coast.
After receiving record-breaking rain in June and July, parts of western Queensland have received their best August rain in nearly 20 years.
August temperature and rainfall records have been broken across Queensland today, some of which have been in place for more than a century.