On 22 October 2013, air quality levels within the Sydney region were measured at 50 times worse than normal, due to smoke from bushfires and backburning in rural New South Wales.

Air quality measurements at the NSW Office of Environment and Heritage were among the highest ever recorded on the air quality index, with pollution readings of up to 2500. Anything above 100 is considered poor air quality.

As a result, there was a significant increase in the number of people treated for asthma and breathing problems. NSW Health recorded that at the height of the bushfires, 228 people attended hospital with breathing difficulties and 778 others were treated by NSW Ambulance staff. The environmental branch within NSW Health reported a 124 per cent increase in patients with asthma conditions seeking hospital treatment.

The blanket of haze continued at varying levels for a couple of weeks. On 2 November, smoke again engulfed Sydney, setting off hundreds of automatic smoke alarms in the city and surrounding districts. The number of call outs for NSW Fire and Rescue increased from an average of 15 per day to 200 within a two hour period.