The season at a glance

Air quality was below national benchmarks on 79 of 92 days (86% of the season). PM10 was the only pollutant to exceed benchmarks, with 13 exceedances recorded. Warkworth experienced the most exceedances.

What affected air quality

Locust dust - Seven sites recorded PM10 exceedances during autumn: Bulga, Camberwell, Maison Dieu, Warkworth, Mount Thorley, Singleton NW, and Singleton South. Nearby mining activity likely contributed to these exceedances.

Other pollutants – PM2.5, ozone, nitrogen dioxide and sulfur dioxide all remained below national benchmarks.

Across the network – Warkworth recorded the highest number of exceedances, with 11 days. Singleton South was the only site to record a day in the Extremely Poor AQC.

Trends

Season

National benchmarks were exceeded on 13 days in autumn, compared with 11 days in summer. Local dust likely drove the exceedances in autumn, while bushfire smoke was the leading cause of exceedances in summer.

However, the summer result may underestimate the number of exceedance days because no valid PM10 data was available from Warkworth, which typically records the highest number of dust-related exceedances. This limits comparisons between the two seasons.

Autumn 2026 recorded the highest number of autumn exceedances since 2019. This was likely due to lower-than-average rainfall and higher-than-average maximum temperatures contributing to more dust generation .

12-month review

Rolling 12-month PM10 and PM2.5 averages to May 2026 were below the annual benchmarks at 13 stations. Warkworth had exceeded the annual PM10 benchmark in the previous two periods ending in May 2024 and May 2025. However, insufficient valid data was available at Warkworth to assess its 12-month average to May 2026.