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.
Road houses and hotels along South Australia's west coast are preparing for a deluge of disappointed Eagles supporters, many of whom will likely make the journey home through the outback in sweltering heat.
When humidity starts to rise and the fish start to bite in the Northern Territory, the locals know the Build-Up is here.
Spring is a season of significant weather variations, ranging from frosty mornings to oppressive heat.