Air Quality Categories

Air quality was generally good across the Newcastle region during spring 2025, remaining below national benchmarks on 85 days (94% of the season).

The Newcastle region recorded the following air quality categories (AQCs) for spring 2025:

• Below benchmarks:
  • Good AQC: 45 days (50.5% of spring days)
  • Fair AQC: 39 days (43%)
• Above benchmarks:
  • Poor AQC: 5 days (5.5%)
  • Very Poor AQC: 1 day (1%)

Exceedances

PM10 and PM2.5 levels exceeded national benchmarks on 6 days across all six monitoring stations during spring 2025. Bushfire smoke is attributed to 3 days above national benchmarks in November (dust also contributed on 14 November). Local dust was attributed to exceedances on 2 days during spring, while sea salt likely caused 2 exceedances at Stockton.

There were no exceedances of national benchmarks during spring 2025 for nitrogen dioxide, sulfur dioxide, ozone or of the ammonia assessment goal.

Trends

Season

Spring recorded a higher number of benchmark exceedances (6 days) compared to winter 2025 (2 days). However, there was a significant increase in the proportion of Fair AQC days in spring (39 days) compared to winter (13 days). The Newcastle region recorded 6 days above national benchmarks compared to 12 days in spring 2024 and 24 days in spring 2023. This is likely due to Stockton recording the fewest hours of onshore winds in spring 2025 than any other spring over the past 11 years. This likely led to fewer PM10 exceedances at Stockton from sea salt during the season. Spring 2025 had a similar proportion of Fair AQC days to spring 2024 and 2023.

The 6 exceedance days occurred in the second half of spring, due in part to bushfire smoke. It is possible the below average rainfall and highest on record maximum temperatures the Newcastle region experienced during spring took time to impact air quality in the region. This might be due to the average temperatures and very much above average rainfall recorded during winter.

12-month review

With the exception of PM10 at Stockton (30.0 µg/m3), all other 12-month rolling PM10 and PM2.5 averages remained below the national benchmark in the 12 months to the end of November 2025. Levels were similar to the previous 12-month period ending November 2024. In general, both PM10 and PM2.5 12-month rolling averages are stable at levels below those recorded before the 2019-2020 bushfire season.