Fires burning across NSW

Firefighters continue to battle up to 100 fires burning across NSW as a large swath of the state wakes to a day of total fire bans.

Record-breaking hot temperatures, storms and wild winds on Friday sparked and fuelled a series of bushfires, mostly in remote and inaccessible terrain in the Blue Mountains, the Hawksbury region, and the state's northeast.

The NSW Rural Fire Service (RFS) says more extreme heat is on the way, propelling the "difficult and challenging" conditions for firefighters on Saturday.

The blazes of most concern are within the Hawksbury region, near Mt Irvine, Bilpin, St Albans, Bowen Hill and Mountain Lagoon, the RFS says.

The fires were moving slowly late on Friday as crews worked with heavy machinery to establish containment lines.

No homes are under threat at prpesent, but residents of Bilpin and Mountain Lagoon are advised to activate their bushfire survival plan.

Community meetings will be held at Bilpin Public School on Bells Line of Road and the Mountain Lagoon Rural Fire Brigade station at 10am (AEDT) on Saturday.

St Albans residents are urged to monitor the RFS website for updates on the Webbs Creek fire, burning about 11km to the west of the town.

A number of fires are also alight in remote and rugged terrain within the Blue Mountains and Lithgow areas, including one about 1km northeast of Bell, and another 4km west of Mount Wilson.

Firefighters worked overnight to construct containment lines which will be strengthened with the use of heavy machinery and aircraft on Saturday.

A community information point will be established at the Mt Wilson Rural Fire Brigade station, where residents can receive updates and advice on Saturday.

The extreme conditions forced the closure of the Blue Mountains National Park, which will remain shut until further notice.

Further north, near the Qld border, two fires are burning at Silent Grove and Flagstone Creek in the Torrington area.

No properties are under threat from these fires, which have razed about 350 hectares of bushland.

Crews are also working to contain a fire at Bingara Road, about 40km north east of Narrabri, and another scrub and grass blaze 10km south of Inverell.

A total fire ban has been issued for Saturday in the Greater Hunter, Greater Sydney, central ranges, northern slopes, north western, upper central west, lower central west, far western and central ranges regions.

"Basically it's very hot and very dry ... it will be a trying day," RFS spokesman Mark Sullivan said.

"It doesn't look like there will be any reprieve for the Sydney basin until Sunday."

Temperatures in the Hawksbury region are expected to top 37 degrees on Saturday, with the mid-30s forecast for the Blue Mountains area.

Extreme conditions of about 38 degrees are expected for Inverell, Mr Sullivan said.

- AAP