A number of hazard reduction burns will be carried out in the Engadine and Menai areas over three days.
Fire agencies will take advantage of forecast mild conditions and undertake the burns starting on Thursday.
There is likely to be significant smoke in the area and residents are advised to take suitable precautions.
On August 15, Fire & Rescue NSW and NSW RFS crews will undertake a 1.2 hectare hazard reduction burn between Gwydir Street and Mount Carmel Place at Engadine.
The following day, Friday, crews will carry out a 1.1ha hazard reduction burn between Berry Grove, Clothier Road, Boxsell Close, Allison Crescent and Tonkies Place at Menai.
On Saturday, NSW RFS crews will undertake a larger hazard reduction burn in the Still Creek valley between Menai and Illawong. The burn is 28ha in size.