Team leader air and terrestrial science Nick Talbot said a long period of high particulate concentrations during the early morning were contributors.
It was the first time in four years the national standard of 50 micrograms per cubic metre of air of PM10 concentration was exceeded in the town as it reached 51.43 micrograms.
The figure was recorded last Thursday at the Gore monitoring site, in Main St, where it had been measured from since 2008.
PM10 are fine particulate matter smaller than 10 micrometres in diameter.
They are formed through the combustion of fuel, atmospheric reactions and mechanical processes.
"It was an unusually high concentration during that day
"Compounding the early morning high concentrations, that evening saw some of the highest PM10 concentrations of the winter to date.
"This was likely due to cold temperatures and low wind speeds allowing pollution from home heating to accumulate."
Between 2am and 8am last Thursday, PM10 concentrations had been unusually high.
Pollution plumes or smog clouds had been active because of low winds, likely contributing to the high reading, he said.
According to MetService, the peak wind gust was 15kmh that day.
It was "disappointing" to see Gore have an exceedance after four years.
"That morning bit is usually quite low ... we don’t know why it [was so high]."
He believed much of the air pollution in Gore came from wood and coal burning.
"So when it is cold, there’s more wood burning so there’s more pollution."
It was important to continue reducing air pollution, as air quality could affect people’s health.
"It might not be quite as clean in Gore during the night as many think."
He encouraged people to keep warm but offered tips on how to do so with minimal environmental impact.
"If you are using a wood or coal burner your pollution will pollute the airshed."
The best tip to reduce smoke impact and get the most value for your wood was to keep fires burning hot and bright, burn dry wood, do not bank your fire overnight and make sure the flue was clean and burner well maintained.
As of January 2022, any wood burner in Gore that was installed before January 1, 2001, must now be replaced by a compliant burner.
