Important information Accuracy of PM2.5 readings in AirRater


Where does AirRater get its air quality information from?

The air quality (PM2.5) information in AirRater is drawn directly from government air quality monitors in all states and territories across Australia. We draw data only from government monitors, so we can be sure the information is coming from reliable sensors in suitable locations.

This means the readings in AirRater are a good guide to air quality in areas close to these monitors.

You can see the location of the air quality monitors that feed into AirRater by going to the Maps view, toggling to ‘Layers’, and selecting ‘Monitoring Stations’. You can also tap on any monitoring station and see the direct reading from that station.

For more information about PM2.5 numbers, see here.


How accurate is the information in AirRater?

In areas within 20 km of a monitor, the numbers you see in AirRater will be based directly on the data from the monitoring stations.

In areas more than 20 km from a monitor, we use a global model of smoke pollution (similar to a weather model) to estimate air quality.

This model is called CAMS, and you can find more information here: https://atmosphere.copernicus.eu/

The CAMS model is the best way we have of estimating air quality in Australia beyond the air quality monitoring network. But in bushfire and smoke situations, this model is not accurate or up to date enough – for example, it only updates about every six hours and doesn’t have the best information about fire location and size.

The estimates from the model will therefore be less up to date and less reliable than those from an actual monitor. Sometimes they can be wrong.


How do I know if I am seeing data from a monitor or the CAMS model?

We have just released a major change to the app that makes it clear when the air quality information is coming from a monitor vs the CAMS model.

With this upgrade, regions using the CAMS model will only give an indication of ‘likely good’ or ‘likely poor’, and the colours on map and dials will be different compared to where you are seeing numbers drawn directly from a monitor.

If you haven’t already updated the app, please update via Google Play or the Apple app store.


What should I do if I am in an area not covered by the air quality network?

In Australia we currently don’t have a good way of estimating air quality in areas away from air quality monitors.

If you are in an area that isn’t covered by the air quality monitoring network, you can look at the estimate from the CAMS model in AirRater, but please be aware that this estimate won’t necessarily be up to date or reliable.

As an alternative, you could also look on the map in AirRater to find your closest monitoring station and use these values as a guide.

However, especially if you are a long way from a monitor, it may be best to trust your senses – visibility is a very good guide to how smoky it is, as well as how strong the smell of smoke is.


One more point to note…

In most states and territories, we receive updated data from monitors every hour and the figure you see is an hourly average. This is the most frequent data available. However, bushfire smoke conditions can change rapidly, and there can be a short lag before the readings catch up. Occasionally, data feeds from monitors can also go down, especially in bushfire affected areas where infrastructure can get damaged.