Air quality data

One of the main air pollutants in Canterbury is airborne particles or particulate matter (PM). These particles are defined by their size, with particles smaller than 10 micrometres referred to as PM10 and those smaller than 2.5 micrometres as PM2.5. It is important to know that PM10 includes all the PM2.5 particles and larger particles up to 10 micrometres in size.

We monitor PM2.5 and PM10 concentrations in our region's eight airsheds. This allows us to compare concentrations with national standards, assess variations over time and understand local variations such as weather. View the latest air quality science snapshot report (PDF file, 2.04MB)

Real-time air quality monitoring data

The table below shows the daily average PM10 and PM2.5 concentrations measured yesterday. Also shown are the number of high air pollution events so far this calendar year (table and map). That is the number of days when the average PM10 concentrations were greater than 50 micrograms per cubic metre of air (µg/m3) and when average PM2.5 concentrations were greater than 25 µg/m3.

Click on a town to see hourly concentrations from yesterday and today, daily average concentrations this year and the number of high air pollution events so far this calendar year, i.e. when pollution levels exceeded national standards and regional targets. Where there are multiple sites in an airshed, like Christchurch, one event is recorded for the airshed if concentrations at any or all sites exceed standards/targets on one date.

These data have undergone preliminary checks only and may change after further validation.

View air quality trends

How our PM monitoring system works

We are transitioning to new methods to measure PM. The older method (TEOM with FDMS) uses a small pump that sucks air through a filter at a constant rate. PM is collected on top of a vibrating filter which changes the frequency of the vibrations. The amount of PM is calculated from the change in vibration and is reported as a one-hour rolling average updated every six minutes.

The newer method (Fidas) uses a laser to measure the light scattered by particles. This enables us to measure multiple particle size ranges at the same time and at time periods of a minute or less.

Hourly PM concentrations are averaged into a daily concentration (midnight to midnight).

Daily concentrations are used to determine the quality of our air and track our progress against targets set for airsheds in Canterbury, based on the National Environmental Standards for Air Quality.

Meeting the National Environmental Standards for Air Quality

The Canterbury Air Regional Plan will help us to meet national air quality standards. The plan sets out how we are going to manage air pollution from home heating, industry, and other sources like outdoor burning, dust and odour. It has a 2030 target for no daily average PM2.5 concentrations greater than 25 micrograms per cubic metre of air. PM2.5 is used in the plan as the PM10 exceedances in most Canterbury airsheds are largely due to PM2.5 from home heating.

Additional monitoring data

We have also measured gaseous pollutants, such as carbon monoxide, sulphur dioxide and nitrogen dioxide which do not exceed the National Environmental Standards for Air Quality. You can find this data on the Land Air Water Aotearoa (LAWA) website.

For daily and hourly concentrations, visit our Open Data Portal.