Air Quality

Air quality in Canterbury is generally good but some of our towns and cities have an air quality problem during winter, most of it due to home heating. All current and previously monitored towns are listed in the Towns tab.

You can find information for all current and previously monitored towns on LAWA and see how they compare from year to year, and against the national guidelines. Environment Canterbury has monitored air quality in 13 Canterbury town and cities and in total there are 56 sites where air quality is, or has been, monitored.

During the winter our cold, still, frosty days mean the smoke from home heating isn’t blown away overnight and gets trapped until morning, when the air warms up or the wind picks up. The particulates from this smoke (and from sea salt, dust and cars) are known as PM₁₀ and these tiny particles can get deep in to our lungs and cause health issues for some people.

PM_2.5 is a subset of PM₁₀ and the main source of PM_2.5 in Canterbury towns and cities is from smoke from home heating. Other sources of PM₁₀ may include industrial and commercial processes, motor vehicles and rural burning, as well as natural sources.

Annual average PM_2.5and PM₁₀ concentrations in most towns are below national guidelines. During still, cold days in winter, daily average PM_2.5and PM₁₀ concentrations can exceed national guidelines, with the main source of emissions usually being from home heating.

We all have a role to play in achieving cleaner, healthier air to breathe and Environment Canterbury has been working with the community to improve air quality, and we’ve seen significant improvements since the late 1990s. Find out about our community programme here (WarmerCheaper.co.nz).

As part of its air quality programme, Environment Canterbury has worked with the community to develop the Canterbury Air Regional Plan which includes measures to manage all contaminants and meet national health-based guidelines.
The National Environmental Standards require no more than one day per year when PM₁₀ is greater than 50 ug/m³ from 1 September 2020.

Regional Summary

PM₁₀and PM_2.5at towns in this region

The most significant air pollutant in New Zealand are small airborne particles in our air (known as particulate matter). Particulate pollutants are of most concern in New Zealand because of their high concentrations in some of our towns. Exposure to high levels of airborne particle pollutants has the potential to cause respiratory and cardiovascular issues. View a factsheet on why air quality is important here.

PM₁₀ and PM_2.5 are the main concern in Canterbury towns and cities. Exposure to PM can have short and long term health effects, and you can see both daily and annual PM concentrations below for each year chosen. Trends in the annual average are reported for the last ten years. Only one currently monitored site for each town are reported in this Regional Summary. In Christchurch this is the St Albans EP site in 2022 and 2023 only. In Timaru this is the Anzac Square site since 2006. There is more information about other monitoring sites in each Town Summary.

PM monitoring history at towns in this region

Annual average
Highest daily average
Exceedance

Showing:

PM₁₀

What is this showing me?

The graph enables you to view the annual average and highest daily average concentrations of PM₁₀ and number of exceedance days for the year selected. The results are compared to the relevant air quality standard or guideline (denoted by the red horizontal line). See this factsheet for more information about the PM₁₀ measurements, and the standards and guidelines used to report on.

Values above the standard or guideline shown can be a cause for concern as short- or long-term exposure to high PM₁₀ can have health impacts. See this factsheet about why air quality is important and factors that influence air quality.

The trends in the table below indicate whether the PM₁₀ concentrations have been improving, showing no measurable change, or declining over the 10-years prior to the year selected. (For towns that have more than one monitoring site, a representative site is shown).

Data table PM₁₀

Towns	10-year Trend	annual average (µg/m³)	Highest daily average (µg/m³)	2nd highest daily average (µg/m³)	Number of exceedances

PM_2.5

What is this showing me?

The graph enables you to view the annual average and highest daily average concentrations of PM_2.5 and number of exceedance days for the year selected. The results are compared to the World Health Organization guidelines (denoted by the red horizontal line). See this factsheet for more information about the PM_2.5 measurements, and the standards and guidelines used to report on.

Values above the guidelines can be a cause for concern as short- and long-term exposure to high PM_2.5 values can have health impacts. See this factsheet about why air quality is important and factors that influence air quality.

Any trends in the table below indicate whether the PM_2.5 concentrations have been improving, showing no measurable change, or declining over the 10-years prior to the year selected. (For towns that have more than one monitoring site, a representative site is shown).

Data table PM_2.5