Hawke's Bay's air is finally meeting national environmental standards, as survey data shows the region's stark reduction in emissions over the past 15 years.
Both Napier and Hastings met their national air quality targets for the winter of 2020, a season that was warmer than normal.
Air-quality rules are set under a National Environmental Standard and allow for one annual exceedance up to an average of 50mg of PM10 over a 24-hour period in Napier, and three for Hastings.
Napier has not had any air quality exceedances in the past five years and Hastings has had a solid decline, with just one this year.
It's a result that remains worth celebrating, without getting complacent, Hawke's Bay Regional Council says.
A home heating survey, conducted by the council, has now shown the scale of the reduction in PM10 (Particulate Matter smaller than 10 microns) emissions over the past 15 years, since the council's Heat Smart programme began.
The survey, which asked more than 1000 people about their home heating in Napier, Hastings, and Havelock North, showed significant reductions in PM10 emissions from 2005 to 2020.
The survey also looked at transport, shipping, industrial and commercial activities, as well as domestic outdoor burning.
HBRC principal scientist air Kathleen Kozyniak said the areas in and around the twin cities had cleaner and healthier air as a result of meeting the targets.
On an average winter night in 2005 in Hastings, 1600kg of PM10 would be emitted across the three urban areas.
In 2020, it averaged 522kg.
"While the results are positive for our region, they don't mean we can be complacent. We still need to aim higher for the health of our community."
Kozyniak said domestic heating was the main source of air pollution in monitored areas of Hawke's Bay, responsible for about 85 per cent of daily emissions in winter.
Shipping and outdoor burning ranked well below it.
HBRC sustainable homes programme manager Mark Heaney said the reductions could be put down to large-scale switches from wood burners to cleaner heating.
"Since 2005, we have replaced 12,067 wood burners, which shows how much the community care about protecting their air quality and their health."
Declines in emissions would continue to reduce slowly, mainly through improved house insulation, burning only dry untreated wood, efforts to reduce outdoor burning and improvements in emissions from industry, Kozyniak added.