A total of 24 breaches of PM10 limits were recorded by the Otago Regional Council (ORC) last month - the same amount recorded during the same time last year.
Latest figures also indicate a rise in breaches in Cromwell and Milton.
Five breaches were recorded in Cromwell in June this year compared to one in June 2018 and eight breaches in Milton in June this year compared to four during June last year.
PM10 are particles in the air less than 10 microns in diameter.
They are produced by the combustion of wood and fossil fuels, as well as by various industrial and natural processes.
Arrowtown continues to be the biggest culprit as 10 breaches were recorded in June by the regional council, compared to 15 during June last year.
Niwa (National Institute of Water and Atmospheric Research) is also conducting air quality checks over winter in Arrowtown and confirmed it had identified national standard breaches six times in one week, between June 19 and 26.
Four sites are monitored continuously year round by the regional council, comprising Alexandra, Arrowtown, Mosgiel and Central Dunedin.
Additional monitoring also occurs in Balclutha, Milton, Clyde, and Cromwell during the winter months.
Other breaches recorded last month included one in Clyde, the same number as last June.
In Alexandra, no breaches were identified last month, or during June 2018.
Niwa scientists had previously said the town was known for having one of the worst air quality levels in the country.
Regional council environmental data scientist Sarah Harrison said concentrations of PM10 had been comparatively lower since the monitoring site was moved to Alexandra Primary School in 2017.
"The site move means it is difficult to confidently identify trends, but as monitoring continues in the new site we will be able to gather a clearer picture of PM10 levels in Alexandra."
Ms Harrison said the regional council expected to see elevated levels as temperatures decreased and people began to heat their homes.
A total of 25 breaches were recorded in Otago last July, including eight in Cromwell.
Ms Harrison said the regional council was engaging in an education campaign across Otago, particularly Arrowtown, to encourage people to burn dry wood which produced less PM10.
"We are also offering a Clean Heat Clean Air subsidy to swap out outdated burners for ultra-low emission heating appliances in qualifying towns."
Niwa has installed 22 outdoor sensors in spots around Arrowtown as part of initiatives launched to encourage good heating habits.
An additional 21 homes have participated in the project by hosting an indoor air quality monitor to detect how much smoke from outdoors is getting into their homes.
The initiatives are part of joint efforts between the regional council, the Southern District Health Board, Cosy Homes Trust and Niwa.
Niwa air quality scientist Dr Ian Longley said the new Arrowtown outdoor sensors and indoor air quality monitors could be rolled out in other spots in the region in the future.
He said it was too early to draw conclusions on any trends in Arrowtown.
"Early indications are that Arrowtown's air quality isn't uniform and that smoke moves around the town in a complex way," he said.
