Levels of nitrogen dioxide, sulfur dioxide and carbon monoxide easily met national standards.
Ozone levels improved compared with 2017, meeting the national standards on 98% of all days. Particle levels increased across the State due to dust from the widespread, intense drought and smoke from bushfires and hazard reduction burning.
Air quality levels vary across the State. Overall, air quality met standards for 98% of days during the year on the Central Coast through to 87% of days in South West Sydney.