Agriculture Weather


Southern Oscillation Index

  • location
  • Aus

The Southern Oscillation Index (SOI) is calculated from the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin.

A strongly and consistently positive SOI pattern (e.g. consistently above about +6 over a two month period) is related to a high probability of above the long-term average (median) rainfall for many areas of Australia, especially areas of eastern Australia (including northern Tasmania) - La Niña.

Conversely, a 'deep' and consistently negative SOI pattern (less than about minus 6 over a two month period, with little change over that period) is related to a high probability of below median rainfall for many areas of Australia at certain times of the year - El Niño.

However, it is important to remember that the pattern of relationship between SOI and rainfall (and temperature) can vary depending on the particular season and region. Additionally, the change in SOI over a specified period can be as important in understanding relationships between SOI and rainfall as is the absolute value in SOI.

Southern Oscillation Index

SOI

Nino3.4 Index

Nino3.4
Display Your Local Weather

Weather News

German reporter suspended after footage showed her smearing mud on herself while reporting on floods

01:31 EST

A German TV reporter has been suspended after video footage showed her smearing mud on herself while reporting on devastating floods in the country.  German TV station RTL suspended presenter Susanna Ohlen after the footage surfaced online.

Monsoon rains trigger landslides and floods in India's Maharashtra state, leaving at least 67 dead

21:39 EST

At least 112 people have been killed in the western Indian state of Maharashtra by torrential monsoon rains that have caused landslides and flooded low-lying areas, cutting off hundreds of villages.

Get a sneak peak into the new Weatherzone Beta website experience while we continue to build out its full functionality.
Explore new datasets, map layers, 7-day charts, 12-month trends and much more!