The NSW Rural Fire Service has warned property owners to think twice before burning off on Wednesday, as temperatures rise to the mid-20s amid winds of up to 70km/h.

Firefighters were kept busy at the weekend with "irresponsible" and "careless" landholders behind dozens of escaped and illegal burns in windy conditions, some of which threatened homes.

Some 48 incidents were reported across the state between Friday and Sunday, 10 more than the previous weekend.

Commissioner Shane Fitzsimmons said the activity was extremely concerning.

"Escaped fires pose a very real and potentially deadly threat to the public, especially if that escaped burn takes hold and fire authorities are not notified," he said in a statement.

Landholders who fail to notify authorities and neighbours face fines of up to $5500 and/or 12 months in jail, while escaped fires can attract penalties of up to $110,000 and/or five years' prison.

"Don't be the fire risk to your community, know your obligations if conducting burns and know the costs if you do the wrong thing," Mr Fitzsimmons said.

The bush fire danger period has already begun in parts of the state, including Lismore, Richmond Valley, Armidale and Walcha. It will start in other local government areas, such as Coffs Harbour and Kempsey, from Friday.

Australian Associated Press