The blaze has currently burnt out more than 41,000 hectares of the Wollemi National Park, Putty State Forest and Coricudgy State Forest, taking in the Muswellbrook Shire, Singleton and Mid-Western Regional LGAs.

NSWRFS Cudgegong district deputy incident controller Inspector Troy Gersback said the rating was increased on December 10 as a result of further fire activity on the eastern edge towards Gum Tree Hole.

"Under forecasted conditions, we will likely see the fire progress to assets located along Putty Valley Road, between the 695 and TJs fires from the 2018/19 fire season," he explained.

"Residents and landholders in this area should monitor conditions closely and be ready to take action should they continue to deteriorate.

"On the western edge of this fire, earth-moving machinery continues to establish and consolidate containment lines throughout the area.

"A back-burn was completed yesterday afternoon/evening in the vicinity of Bin Ben Mountain, Native Dog Hill and the Wilderness Bunkhouse.

"The containment strategy for this area is to hold the fire south of the Coricudgy Road.

"Due to rugged terrain, this fire continues to burn un-contained to the north (south of properties along Widden Valley Road, Blackwater Creek Trail and Baerami Creek Road)."

Listed as 'Being Controlled', the Meads Creek West fire has currently burnt out more than 21,000 hectares of the Goulburn River National Park and adjoining private property.

Firefighters - supported by earth-moving machinery and water-bombing aircraft - continue to work across the fire ground to consolidate and establish containment lines.

Back-burning operations were conducted in the vicinity of Hamburger Hill yesterday afternoon/evening to prevent potential fire escape into neighbouring farmland.

Further back burning operations will be completed when conditions allow.

Ringwood Road remains closed.

This closure will be reviewed Wednesday afternoon.

Listed as 'Being Controlled', the Oaky Creek fire has currently burnt out more than 3500 hectares of the Wollemi National Park.

Firefighters - supported by local landholders, earth-moving machinery and water-bombing aircraft - continue to work on establishing containment lines and extinguishing the fire as it moves out of the national park onto open country.

Due to rugged terrain, this fire continues to burn un-contained along the south-eastern corner towards isolated properties situated along Nullo Mountain Road.

Residents and landholders in the vicinity of these fire grounds should continue to remain vigilant and monitor the situation closely.

Check and follow your Bush Fire Survival Plan.

If you do not have a plan, know what you will do in the event you come under direct threat.

Remember - leaving early is your safest option.