Nelson at St Vincent St

The dashboard colours show how PM₁₀ levels sit in relation to guidelines – from dark blue (less than 10%) to red (more than 100% of the guideline).  The guideline (100%) value for the daily average PM₁₀ is 50 µg/m³ and  20 µg/m³  for the annual average.  There are no guidelines for hourly or monthly data (charcoal colour). 

If a site has less than two days of PM₁₀ exceedances each year, this is compliant with the NES-AQ.  If there are two or more exceedances annually, then the site does not comply with the NES-AQ.

This graph shows how levels of PM₁₀ change on an hourly, daily, monthly or annual basis for the selected time period. The levels depend on local sources of emissions and what the weather is doing.  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 goes 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.   The PM₁₀ concentrations are shown against the guidelines for air quality (for daily and annual averages), and where concentrations exceed the guideline (red line) this can be a cause for concern, especially if this occurs on a frequent basis.   

Exceedance data (when available) shows the number of days per year that the concentrations went above 50 µg/m³.  

The World Health Organization published new guidelines in September 2021 of 45 µg/m³ for daily averages and 15 µg/m³ for annual averages.

For information about allowable exceedances and targets, and the limitations of data shown, see the Factsheet on monitoring air quality in New Zealand. 

The dashboard colours show how PM_2.5 levels sit in relation to the guideline – from dark blue (less than 10%) to red (over the guideline).  The guideline (100%) value for  the daily average PM_2.5 is 25 µg/m³ and 10 µg/m³ for the annual average.  There are no guidelines for hourly or monthly data (charcoal colour).

If a site has less than four days of PM_2.5 exceedances each year, this is compliant with World Health Organization 2005 guidelines.  If there are four or more exceedances annually, then the site does not comply with these guidelines.

This graph shows how levels of PM_2.5 change on an hourly, daily, monthly or annual basis for the selected time period.  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 goes 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.   The PM_2.5 concentrations are shown against the guidelines for air quality (for daily and annual averages), and where concentrations exceed 100% of the guideline (red line) this can be a cause for concern, especially if this occurs on a frequent basis.  

Exceedance data (when available) shows the number of days per year that the concentrations went above 25 µg/m³.  

The World Health Organization published new guidelines in September 2021 of 15 µg/m³ for daily averages and 5 µg/m³ for annual averages.

For information about allowable exceedances and targets, and the limitations of data shown, see the Factsheet on monitoring air quality in New Zealand.