Monitoring the environment

Hourly air quality data table


This bulletin is updated hourly with data readings averaged over the previous eight hours for carbon monoxide, the previous 24 hours for PM2.5 and the previous hour for PM10, ozone, nitrogen dioxide, sulfur dioxide and visibility reduction. Detailed information on the calculation of the air quality index (AQI) is available below.

Please see the summary below for an indication of expected air quality. On occasion, data may not show on the table below for a variety of reasons, such as monitoring station maintenance, equipment breakdown or website issues. See current notices below.

During winter months, EPA switches off equipment that we use to monitor summer ozone in parts of our network (mostly in metropolitan Melbourne). We will switch them back on before the start of next summer.

*Important information about monitoring PM2.5

As of 28 June 2015 EPA now reports on PM2.5 levels at nine additional sites. These are: Box Hill, Brighton, Dandenong, Mooroolbark, Altona North, Melton, Point Cook, Macleod and Wangaratta. At these sites, PM2.5 is measured using portable air monitoring monitors. All other stations that record PM2.5 use a monitor called a BAM (beta attenuation monitor). These monitors produce data that is a rapid assessment of PM2.5 levels in an area. EPA has done work with these types of monitors that shows they can correlate well with measurements from a BAM. We are currently working to better understand the precision of this equipment. We are doing this by comparing data from portable monitors with data from other types of particle monitors. These mobile instruments provide the community with a more flexible air monitoring network by allowing EPA to monitor air quality at a greater variety of sites. Find out more about the differences between the different kinds of air monitoring equipment and methods.

Data for a given hour are available at 30 minutes after the following hour. For example, data for the period from 9 am to 10 am is available at 10.30 am. See the Q&A below for more information about station summaries, ‘not available’ and ‘offline’ reports.

Current notices

  • Monitoring for PM10 at Geelong air monitoring station is offline due to routine maintenance and PM10 data is not being collected at this station. EPA expects data to become available on the website from 11am on 26/09/16. The air quality forecast for Melbourne is expected to be GOOD to VERY GOOD. (23 September 2016)

  • Monitoring for PM2.5 at Footscray air monitoring station is offline due to routine maintenance and PM2.5 data is not being collected at this station. EPA expects data to become available on the website from 11am on 26/09/16 . The air quality forecast for Melbourne is  GOOD to VERY GOOD. (20 September 2016)

  • Monitoring for PM2.5 at Box Hill air monitoring station is offline due to technical difficulties and PM2.5 data is not being collected at this station. EPA technicians are working to fix the problem. (19 September 2016)
  • EPA is looking for a new site for its Richmond air monitoring due to problems with access at its existing location. Interim monitoring equipment will soon be installed in a location near Melbourne’s CBD to monitor PM2.5. Until the new location is confirmed, air monitoring data from Richmond will not appear on EPA’s AirWatch website. (16 September 2016)

  • Monitoring for PM2.5 at Morwell East air monitoring station is offline due to technical difficulties and PM2.5 data is not being collected at this station. EPA technicians are working to fix the problem. (1 September 2016)

  •  EPA is improving its air monitoring network to enable it to measure air quality beyond Melbourne, Geelong and the Latrobe Valley. To give EPA’s network more coverage, we have removed ozone and visibility equipment from the Box Hill and Brighton monitoring stations for use in other areas; however both stations will continue to monitor small particles known as PM2.5, a key indicator of air quality. (12 August 2016) 

EPA collects air quality data using a variety of different monitoring instruments, which are placed in strategic locations – these instruments make up our ‘air monitoring network’. Find out more about EPA’s air monitoring network and what we monitor.

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Page last updated on 23 Sep 2016