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.
Newcastle locals hoping for a morning swim ahead of a sweltering day have been left disappointed, with vandals emptying the city's ocean baths.
A severe weather warning is in place for damaging winds up to 90 kilometres per hour in Canberra today.
High winds overnight in Victoria kept the State Emergency Service (SES) busy with 700 calls for help across the state.