The early arrival of fierce bushfires in the southern spring has already claimed several lives and destroyed nearly 300 homes over the past week.
NSW Police said in a statement that a 51-year-old man has been charged after allegedly lighting a fire which is now out of control in the state's Northern Tablelands.
There were 59 bush and grass fires in New South Wales as of Saturday morning, with 13 yet to be contained, according to NSW Rural Fire Service.
Firefighters strengthened overnight containment lines by back burning around the Gospers Mountain fire, which is blazing across more than 100,000 acres (156 square miles) near Sydney's northwest outskirts.
Back burns are fires deliberately lit to clear dry undergrowth.