Hastings has reached an air quality milestone after being exceedance-free throughout June.
This was the first time since 2006 when Hawke's Bay Regional Council started continuous testing for air quality in Napier and Hastings.
Council climate and air scientist Dr Kathleen Kozyniak said what used to take just one still frosty day to get exceedance now took two.
"There is an overall improving trend and health-wise, any winter month without an exceedance is a win for Napier and Hastings residents."
Dr Kozyniak relies on technical equipment based at Marewa Park and St John's College to measure the National Environmental Standard for particulate matter (PM10). An exceedance is any reading above 50 micrograms per cubic metre averaged over 24 hours.
"The weather itself may have played a part, but I think people's efforts to adopt clean forms of heat are reaping benefits. The aim is to have no more than one exceedance per year by 2020.
If we continue to decrease our emissions we should make it."
Before the council's HeatSmart programme began in 2009, there were a high number of annual exceedances, particularly in Hastings and to a lesser degree in Napier.
HeatSmart was set up to improve air quality in Hawke's Bay by reducing air pollution from home wood burners and fires due to the adverse effects it has on people's health.
Council's client services manager Mark Heaney, who oversees the HeatSmart programme, said since HeatSmart started, more than 9500 fireplaces had been upgraded or replaced along with insulation retrofits and upgrades in many homes.
"In spite of the inversion layer over both cities on cold, still winter nights, the number of exceedances each year has generally been tracking down," Mr Heaney said.
Dr Kozyniak wanted to remind people to continue to be mindful when using a fire and if it looked smoky outside then people should look to improve it.
"Only use dry wood, not treated timber or painted wood when having a fire."
"There has been a good response so far with more people having fires with low emission or using electronic alternatives."
Council chairman Rex Graham said this result was a credit to the community.
"It is wonderful and I think we all need to continue to encourage one another to protect our fresh air."
Open fires inside households in Napier and Hastings air sheds were outlawed in 2012 and non-compliant wood burners will be prohibited for use from January 2018 for Hastings, and from January 2020 for Napier.
There are no restrictions on wood burners outside the city air shed areas.