This statement summarises data collected from the NSW Air Quality Monitoring Network during 2025. It assesses air quality conditions against national standards for the state’s metropolitan and regional centres.

The 2025 statement presents 2 focus areas: 

  • One analyses air quality from stations near industrial activity in the Hunter Valley.
  • The other highlights the 20-year anniversary and success of the DustWatch Program.

The NSW Clean Air Strategy implementation highlights for 2025 are also available.

Summary

Regions across New South Wales met air quality standards at least 93% of the time, except for 2 Hunter stations.

Gases

  • Standards for carbon monoxide, hourly nitrogen dioxide and daily sulfur dioxide were met 100% of the time.
  • Ozone exceeded the standard on 12 days (6, 14–15 January, 28 February, 14–15 March and 6, 9, 18–21 December).
  • The one-hour sulfur dioxide standard was lowered to 7.5 parts per hundred million (pphm) from 1 January 2025. Under this new standard, sulfur dioxide exceeded 7.5 pphm at Morisset (Lake Macquarie) on 27 August and 16 September.
  • Bradfield Highway (East Sydney) was the only station to exceed the annual average for nitrogen dioxide, recording 1.6 pphm for 2025.

Particles

  • The daily PM10 standard was met on all but 36 days in 2025, occurring at 38 stations. This has increased from 18 days at 9 stations in 2024. Exceedances were most common in April (8 days), mainly from local dust, and in December (7 days), mainly from bushfire smoke.
  • The daily PM2.5 standard was met on all but 33 days in 2025, occurring at 31 stations. This is higher than 20 days at 9 stations recorded in 2024. Exceedances in 2025 were most frequent in June (14 days), primarily from wood heater smoke.
  • Above-average temperatures and average rainfall led to more hazard reduction burning and bushfires, as well as expanding areas affected by drought.
  • All stations except Warkworth (Upper Hunter) and Stockton (Newcastle Local) in the Hunter met the PM10 annual standard. All stations met the PM2.5 annual standard.

Hunter Valley

  • Among the larger population centres (excluding Stockton), 13 days exceeded the PM10 benchmark, up from 6 days in 2024.
  • PM10 exceedances occurred on 40 days in the Upper Hunter in 2025, up from 30 days in 2024. This was largely driven by the 14 exceedances at Mount Thorley (Upper Hunter) compared with 6 days in 2024.
  • Warkworth and Stockton exceeded the PM10 benchmark on 30 days (91.7% of the time) and 27 days (92.6% of the time), respectively, predominantly due to mining activity at Warkworth and sea salt at Stockton.

Monitoring network and reporting

  • From 1 January 2025, the one-hour sulfur dioxide standard was lowered from 10 pphm to 7.5 pphm.
  • Data in this report come from 57 stations using compliant ambient air quality monitoring methods, spread across 16 NSW air quality monitoring regions. This includes monitoring in industrial areas, such as the Upper Hunter and Newcastle Local (around the Port of Newcastle) regions.
  • The main report includes data from 46 compliance stations in metropolitan and regional centres, including 9 in the Hunter Valley (excluding Stockton). These data are assessed against national standards.
  • Note the symbology used in this report:
    • ^ Data from Stockton (Newcastle Local region) are excluded.
    • # Merriwa, Aberdeen, Singleton and Muswellbrook are included as Upper Hunter stations.
  • The Hunter Valley focus area includes data from 20 compliance air quality monitoring stations: 14 in the Upper Hunter region, 3 from Newcastle Local and 3 from the Lower Hunter regions. The Upper Hunter and Newcastle Local stations primarily capture local industrial pollutant influences. National standards serve as benchmarks for assessing these data. The Stockton data are presented in this section.
  • Data from the compliance monitoring stations at Cammeray and Millthorpe are excluded from this report, as they are research stations. Similarly, particle data from the 39 indicative air quality monitoring stations in the rural areas were excluded from this report.
  • Note that Ultimo–UTS (East Sydney) came online in July 2025, while Bargo (South West Sydney) was decommissioned in July 2025. Data from both stations are presented in this report; however, annual averages and annual maxima are not calculated, as the stations were in operation for only a partial year.
  • Note that data from 25–31 December 2025 have undergone only preliminary validation.