NSW fire crews and communities are bracing to see the impact of dangerous fire conditions which were fanned by strong and gusty winds throughout Friday night.
Rural Fire Service spokesman Anthony Bradstreet said more than 3500 firefighters were deployed throughout night as they battled a strong wind change which brought 90km/h gusts to dozens of dangerous fire grounds.
"We will see the full impact of the fires reveal itself tomorrow (on Saturday)," he told AAP on Friday.
Three bushfires burning in the south on Friday evening merged to create a massive blaze in the Snowy Mountains region after being fanned by strong winds.
The 233,000-hectare Green Valley fire merged with the nearby East Ournie Creek blaze and the huge 312,000 hectare-Dunns Road fire which were all at emergency level on Friday night.
Mr Bradstreet said the fires were burning very quickly and could impact rural properties in the area.
The southwesterly wind change was forecast to reach Moruya about 11pm and Sydney by 2am on Saturday.
The RFS was also concerned about the Erskine Creek blaze which is an extension of the Green Wattle Creek fire near the Blue Mountains.
It was put at watch-and-act level on Friday evening because of fears strong winds could move it towards Leura and Wentworth falls.
Conditions are due to ease later on Saturday with showers and isolated thunderstorms in coastal parts and adjacent ranges expected.
About 65 of the 137 bushfires burning around NSW are uncontained.
The number of homes confirmed destroyed since January 1 has increased to 1079, the RFS said on Friday.
At least 1995 homes have been lost since the start of the fire season. Another 816 have been damaged.
Since July, 20 people including three firefighters, 6200 livestock and millions of wild animals have died in the NSW bushfires.
