- WEATHER
Australia
- National
- New South Wales
- Victoria
- Queensland
- Western Australia
- South Australia
- Tasmania
- ACT
- Northern Territory
Long Range Forecasts
- WARNINGS
- RADAR
- SATELLITE
- MAPS & CHARTS
- LONG RANGE
Long Range Forecasts
- CLIMATE
Climate Indicators
- NEWS
Search Farmonline Weather Help
Understanding the Weather
What is the Nino3.4 Index?
The Nino3.4 Index, similar to the Southern Oscillation Index, is closely tied in with the El Nino phenomenon. Nino3.4 is the average sea surface temperature anomaly in the area bounded by 5N to 5S and 170W to 120W. Changes in sea-surface temperatures in this region are important in shifting rainfall areas across the far western Pacific Ocean. An El Nino event is indicated if the 5-month running average of the Nino3.4 index exceeds 0.4C for at least six consecutive months. A La Nina event is indicated if this average is below -0.4C for at least six consecutive months.
A graph of the Nino3.4 index is updated weekly on Weatherzone, making it easier to track changes in the Pacific Ocean sea-surface temperatures.
Related Articles
- What is the Southern Oscillation Index?
- What time do the maximum and minimum temperatures refer to?
- Where do the background maps come from in your charts and how is the data turned into graphics?
- Who gives you the information used in your weather charts?
- What does wind chill mean?
- What is relative humidity?
- What is feels like temperature?
- How is the UV index measured?
- How are sunrise and sunset times measured?
- How do I set my barometer?
- How is rain measured? How is snow measured? How do you calculate the water equivalent of snow?
- What are common sources of errors in measuring precipitation?
- What is the dew point?
- Why is wind not always included in the forecast?
- When you talk of a north or northerly wind, do you mean that the wind blows from the north or towards the north? Is this the geographic north of the magnetic north?
- How is a weather forecast made?
- What is the difference between a tropical cyclone, a hurricane and a typhoon?
- Do you have an explanation of the terminology you use in weather forecasts?
Enter a postcode or town name for local weather, or text to search the site. » advanced search
Snowy weekend ahead in the mountains
16:04 AEST Snowfalls last weekend were the heaviest of the 2024 winter in the alpine regions of Tasmania and mainland Australia, and more snow is coming this weekend.
Help with Farmonline Weather
