Since November 26, the uncontained Green Wattle Creek fire has burnt over 124,000 hectares. It impacted the Upper Lachlan Shire last week.

The RFS has advised with hotter conditions forecast for next week the bushfire could break fire barriers being used to control the fire edge. Temperatures are predicted to climb to 40 degrees in the Southern Tablelands, according to the Bureau of Meteorology.

"Heavy machinery is continuing to establish a strategic containment line from Wombeyan Caves to Mount Werong," advice on the NSW RFS Southern Tablelands zone Facebook page said.

"There is active fire south of the Colong Stock Route. Back burning will continue north of the Colong Stock Route between Big Plain and Bindook Highlands."

Residents have been urged to monitor ash from the fires.

For updates follow the RFS Southern Highlands Team (@RFSSHT) on Facebook.

Residents can stay informed on the RFS website rfs.nsw.gov.au or the Fires Near Me app for smart devices.

Stay up to date by calling the NSW RFS Bush Fire Information Line on 1800 679 737. Call triple zero (000) if a fire is active without firefighters in attendance or if your life is at risk.

For information on road closures, check Live Traffic NSW. For information on national park closures, check NSW National Parks.