Forecast accuracy

Find out about the accuracy of our forecasts and how we're improving performance

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Delivering accurate forecasts

Measuring accuracy is a key part of assessing the performance of our forecasts.

We do this by comparing our forecasts to actual weather data. This data is recorded by our observation network.

To improve our forecasts, we increase:

  • understanding of the atmosphere
  • resolution of our forecast models – spatial and temporal
  • number and type of observations these models use
  • skill and knowledge of our forecasters, staying up to date with the latest science.

Temperature forecasts

Temperature forecasts are considered accurate if they were within 2 °C of actual temperatures.

Text over a blue background reads: 91% of temperature forecasts are within 2 degrees. The text is next to an image of two cyclists on a path through green coastal parkland.

Over 2023–24, next day maximum temperature forecasts were accurate 90.9% of the time. Overnight minimum temperature forecasts were accurate 82.4% of the time.

Line graph showing accuracy of next day temperature forecasts over the past 5 years. The accuracy of maximum temperature forecasts rose from about 90% to 91% over this period. The accuracy of minimum temperature forecasts rose from about 80% to nearly 84% in 2022-23. It declined to 82.4% in 2023-24.
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Forecast maximum and minimum temperatures for the next day across 500 locations that were accurate to within 2 °C, showing year-to-year changes

Rainfall forecasts

While weather elements like temperature and wind can be the same across large areas, rainfall varies much more. There can be large differences across small areas as showers move across, raining in some places and missing others. That's why our forecasts include information about the chance of any rain, along with a possible expected rainfall range.

The possible rainfall range indicates the rain that a location may receive. An example of a possible rainfall range is 2–6 mm.

The lower value has a 75% chance of being exceeded and the upper value a 25% chance. If the forecast is reliable, the upper figure should be exceeded around 25% of the time and the lower 75% of the time. (The lower threshold changed from 50% to 75% in 2022.)

In 2023–24, the Bureau's next-day rainfall range values provided a good indication of observed rainfall based on statistical performance metrics.

Bar graph showing accuracy of rainfall range forecasts by the Bureau over the past 5 years from 2019–20 to 2023–24. The graph shows that the rainfall range forecasts provided a good indication of the observed rainfall.
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Accuracy of the rainfall range forecast for the next day across 500 locations when compared to observed rainfall

Wind forecasts

Wind information, particularly wind speed and direction, is important for marine activities, aviation, energy and agriculture. We have a network of wind recorders to verify wind forecasts across a range of urban, rural and coastal areas.

Text over blue background reads: 87% of next day wind speed forecasts for coastal waters are within 5 knots. This text is next to an image of two smiling young people holding hands as they walk along a coastal path at sunset. The ocean is in the background.

In 2023–24, for coastal areas, 87.1% of wind forecasts for the next day were correctly predicted to within 5 knots.

When looking across all urban, rural and coastal areas, 91% of forecast wind speeds were within 5 knots.

Line graph showing that coastal wind speed forecasts for the next day have been 78–87% accurate for the 5 financial years to 2023–24.
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Percentage of wind speed forecasts for the next day across selected coastal locations that were accurate to within 5 knots, showing year-to-year changes

Flood forecasts

We provide flood forecasting and warning services for most major rivers in Australia. To do this, we work with other government authorities, such as:

  • state and territory emergency services
  • water agencies
  • local councils.

To assess forecast performance, we measure the percentage of:

  • peak river height predictions within a specified range of the observed peak – for example, 0.3 m
  • forecasts that meet service level specification targets for lead time to customers.

In 2023–24:

  • 74% of flood forecast peak height predictions met service level specification targets (typically within 0.3 m)
  • 69% of flood forecast lead times met service level specification targets (which vary in lead time for each river).

Learn more about service level specifications in our Flood knowledge centre.

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