St Johns

This graph shows how concentrations of PM₁₀ change on an hourly, daily, monthly or annual basis for the selected time period. The number of exceedance days can be viewed over the last 10 years or all years if available.

The PM₁₀ daily average concentrations and exceedance days are compared to the National Standard (NES-AQ), and the PM₁₀ annual average concentrations are compared to the WHO guideline.  The standard and guideline limits are denoted by the red horizontal line.   There are no guidelines for hourly or monthly average concentrations.  For information about allowable exceedances and targets, and the limitations of data shown, see the factsheet on monitoring air quality in New Zealand. 

The concentrations depend on local sources of emissions and weather conditions. Emissions from various sources change, depending on whether it's a weekday or the weekend or at different times of the year (e.g. emissions from home heating go up in the cold winter months).  Still conditions often lead to high concentrations, as there is no wind to blow away the pollutants in the air.  At some monitoring sites, the hourly temperature and wind data are available to explore the relationship between local weather conditions and PM₁₀ concentrations.  See this factsheet about why air quality is important and factors that influence air quality. 

This graph shows how concentrations of PM_2.5 change on an hourly, daily, monthly or annual basis for the selected time period. The number of exceedance days can be viewed over the last 10 years or all years if available.

The PM_2.5 concentrations and exceedance days are compared to the WHO guidelines.  The guideline limits are denoted by the red horizontal line.  There are no guidelines for hourly or monthly average concentrations.  For information about allowable exceedances and targets, and the limitations of data shown, see the factsheet on monitoring air quality in New Zealand. 

The concentrations depend on local sources of emissions and weather conditions. Emissions from various sources change, depending on whether it's a weekday or the weekend or at different times of the year (e.g. emissions from home heating go up in the cold winter months).  Still conditions often lead to high concentrations, as there is no wind to blow away the pollutants in the air.  At some monitoring sites, the hourly temperature and wind data are available to explore the relationship between local weather conditions and PM_2.5 concentrations.  See this factsheet about why air quality is important and factors that influence air quality.