MEGA GALLERY: Bushfires across Australia

Firefighters have been backburning overnight to try and contain several major bushfires across NSW, taking advantage of the cool temperature before hot, windy weather sets in again.

There are 126 bushfires burning across the state, including 15 that are not contained, on Thursday morning.

Over 1000 Rural Fire Service volunteers are working, using more than 80 firefighting aircraft and 360 trucks.

A bushfire burning 8km south west of Naradhan, north of Griffith in New South Wales. Photo: AFP/NSW Rural Fire Service

RFS Commissioner Shane Fitzsimmons said firefighters are trying to contain the blazes before dangerous fire conditions return on Friday, Saturday and Sunday.

Crews were backburning at the Deans Gap fire, in the Shoalhaven on Wednesday night, but it has not been contained.

That fire has burnt through more than 5700 hectares of land.

Residents in Wandandian, Sussex Inlet, and those south of the coastal villages, are advised to remain vigilant and keep up to date with information.

Firefighters also spent the night backburning at the Cobbler Road fire, near Yass, to establish and strengthen containment lines around the blaze, which has burnt through 14,000 hectares and killed thousands of animals.

A bushfire continues to burn about 20 kilometres east of Cooma, in the state's south, and residents are advised to stay informed.

A fire at Lithgow, which police believe was deliberately lit, is under control, but smoke is still affecting the town and the Bells Line of Road.

Mr Fitzsimmons said people in bushfire prone areas need to stay alert, and not always expect a warning message from the RFS.

"Some fires will start, they will take hold and they will spread so quickly that they could be impacting on people before someone's even had a chance to report it to triple-0, or certainly before the fire engine is able to get on scene," he said.

"Until someone's got that crystal ball that can tell us exactly where that fire is going to be, and start, and exactly what time it's going to be, that's a reality of life."

Total fire bans are in place in the North Western and Northern Slopes regions.

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