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.
Sydney-sider's woke to a blanket of haze this morning, primarily in the north as light westerly breezes wafted smoke from hazard reduction burns inland towards the coast.
Ignorance is a dangerous thing in a country like Papua New Guinea.
Authorities are warning South Australians to brace for widespread heavy rain across the weekend, with the weather bureau forecasting up to 80 millimetres in some areas.