The season at a glance

Air quality was below national benchmarks on 70 of 90 days (77.8% of the season). Sea salt at Stockton and bushfire smoke contributed to the 20 exceedance days.

What affected air quality

Sea salt At Stockton, sea salt contributed to PM10 exceedances on 11 days..

Bushfire smoke Smoke contributed to PM10 and/or PM2.5 exceedances on nine days. Two major bushfire events accounted for 8 of these days: four between 5 and 9 December 2025, and four between 31 January and 7 February 2026. Smoke from Victoria likely contributed to another PM10 exceedance on 11 January 2026.

Local dust and ozone Local dust contributed to PM10 exceedances on three days. Ozone exceeded the benchmark on one day.

Other pollutants  Nitrogen dioxide, carbon monoxide and sulfur dioxide remained below national benchmarks. Ammonia remained below its assessment goal.

Trends

Seasonal

National benchmarks were exceeded on 20 days in summer, compared with 6 days in spring. The increase was mainly due to bushfire smoke in December and from late January to early February, as well as PM10 exceedances from sea salt at Stockton. Rainfall during summer was average.

The 20 exceedance days were similar to those in other recent Newcastle summers. By contrast, summer 2024-25 had only nine exceedance days, one of the lowest totals on record. Wetter conditions likely reduced dust levels and limited bushfire activity that season.

Summer recorded 42 Fair AQC days, similar to 39 in spring and consistent with previous summers. Most Fair days were associated with PM10 from sea salt at Stockton.

12-month review

Rolling 12-month PM10 and PM2.5 averages to February 2026 were generally similar to those for the periods ending February 2025 and 2024. They remained lower than levels recorded before and during the 2019-20 bushfires. PM10 averages were below the annual benchmark at all stations except Stockton, where the 12-month average was 31.1 µg/m³. PM2.5 averages remained below the annual benchmark at all stations.

Higher PM10 and PM2.5 levels at Stockton are consistent with findings of the Lower Hunter Particle Characterisation Study. This study found that PM10 at Stockton was 2 and a half times higher than Mayfield, mainly due to fresh sea salt. It also found 40% more PM2.5 at Stockton than Mayfield, Beresfield and Newcastle. This was due to more sea salt in onshore winds and primary ammonium nitrate in north-west winds, particularly in spring (and very likely due to Orica’s ammonium nitrate manufacturing facility on Kooragang Island).