Air quality data

One of the main air pollutants in Canterbury is particulate matter smaller than 10 micrometres — or PM10. We monitor PM10 concentrations in our region's eight airsheds. This allows us to compare concentrations with national standards, assess variations over time and understand impacts of local weather conditions. Our findings are presented in monitoring and technical reports.

Real-time air quality monitoring data

The table below shows daily PM10 concentrations measured yesterday. Also shown are the second and fourth highest concentrations so far this calendar year. Click on the towns/airsheds highlighted in blue for more information, including hourly concentrations and the number of high pollution nights recorded for the calendar year, i.e. when pollution levels exceeded national standards.

To view air quality data from past years click here.

  • ¹ Yesterday - PM10 concentration yesterday – micrograms per cubic metre of air (ug/m³)
  • ² Second highest - PM10 concentration (ug/m³). These towns are required to have no more than 1 high pollution night per year, i.e. second highest no more than 50ug/m³.
  • ³ Fourth highest - PM10 concentration (ug/m³). These towns are required to have no more than 3 high pollution nights per year, i.e. fourth highest no more than 50ug/m³.
  • These data have undergone preliminary checks only and are subject to further validation.
Geraldine exceedance exemption~~
The Ministry for the Environment has granted an exemption for the PM10 exceedance in the Geraldine airshed on 1 February 2019.

The key aspects of this exceedance are:

  1. It was in February. Most exceedances in Geraldine are in winter.
  2. It was a combination of coarse PM in the early morning during a northwest wind, and a coarse PM peak at midday during a quick change in wind direction to southerly. Each event individually would not cause an exceedance, but the unusual combination of both on the same day pushed the daily average over the standard. Most exceedances in Geraldine are driven by high PM2.5 from smoke.

The cause of the exceedance remains undetermined despite best efforts to ascertain the circumstances. For these reasons, the Minister is satisfied that this exceedance is exceptional, and unlike the “normal” exceedances in this town. Although it will still show in our data as an exceedance, it will not count towards total PM10 breaches in the Geraldine airshed for 2019.

How our PM10 monitoring system works
A small pump sucks air through a filter at a constant rate. The weight of the filter changes with more or less PM10. This changes the frequency of a small vibrating element in the machine. The amount of PM10 is calculated from the vibration. Hourly PM10 concentrations are averaged into a daily concentration (midnight to midnight). Daily concentrations are used to track our progress against targets set for different airsheds in Canterbury, based on the Government's National Environmental Standards for Air Quality.

Meeting the National air quality standards

The Canterbury Air Regional Plan will help us to meet national air quality standards. The plan also sets out how we are going to manage air pollution from home heating, industry and other sources like outdoor burning, dust and odour. 

The Government's National Environmental Standards for Air Quality set different targets for different airsheds.

Christchurch, Timaru, Ashburton, Waimate and Kaiapoi airsheds must experience fewer than three days per year with PM10 over 50 micrograms per cubic metre of air from 1 September 2016 and no more than one day per year from 1 September 2020.

Geraldine, Rangiora and Washdyke airsheds must experience no more than one day per year with PM10 over 50 micrograms per cubic metre of air from 1 September 2016.

Additional monitoring data

We also measure PM2.5 and other gaseous pollutants, such as carbon monoxide, sulphur dioxide and nitrogen dioxide. You can find these data at Land Air Water Aotearoa.

For daily and hourly concentrations of PM10 for another time period, visit our data catalogue.