The season at a glance

Air quality was below national benchmarks on 89 of 90 days (99% of the season). The only exceedance was for PM10 at Wil-gai.

What affected air quality

PM10 exceedance – Wil-gai recorded one day above the PM10 benchmark, when air quality was classified as Very Poor.

Other pollutants – PM2.5 stayed below the benchmark at all 6 stations. Ozone and nitrogen dioxide also remained below benchmarks at Gunnedah and Tamworth, where they are monitored.

Ozone – Ozone at Gunnedah or Tamworth led to 30 of the 31 Fair AQC days. Strong sunlight and high temperatures speed up the reactions that form ozone.

Trends

Seasonal

One day exceeded a national benchmark in summer, compared with none in spring 2025. This is consistent with most recent summers. Rainfall was below to very much below average, and maximum temperatures were very much above average.

Summer 2023-24 was an exception: smoke from the Duck Creek Pilliga Forest bushfire in December 2023 led to six exceedance days.

12-month review

Rolling 12-month PM10 and PM2.5 averages to February 2026 were below the annual benchmarks at all 6 stations. Averages were generally lower than those for the period ending February 2025. 

In the period ending February 2025, PM2.5 exceeded the benchmark at Werris Creek and Wil-gai. 

At Tamworth, Gunnedah, Narrabri and Maules Creek, rolling averages have remained below the annual benchmarks in every 12-month period ending in February since 2021.

The highest particle averages across the six stations occurred in the 12 months to February 2020, when widespread bushfires and dust storms affected air quality.