The "catastrophic" fire warning for parts of the state has been extended to the Illawarra and Shoalhaven regions.
The NSW Rural Fire Service said conditions in the Illawarra and Shoalhaven were expected to be worse than first anticipated, with the regions now forecast to experience "catastrophic" fire danger on Tuesday.
The Bureau of Meteorology has forecast strong winds and low humidity with temperatures of up to 36 degrees expected in Wollongong on Tuesday. A late cool change is expected which will cause temperatures to plummet to an expected 20 degrees on Wednesday.
Shell Cove's Reflections Holiday Park at Killalea Reserve are asking residents and guests to leave, due to the fire danger. All staff will be leaving, and no new guests will be accepted.
The Greater Sydney and Greater Hunter areas are also forecast to experience catastrophic fire danger on Tuesday.
According to the NSW RFS, catastrophic is the highest level of bushfire danger. It's the first time since new Fire Danger Ratings were introduced in 2009 that catastrophic fire danger has been forecast for Sydney.
NSW has declared a state of emergency for seven days starting immediately as bushfires rage across the state.
The fire danger tomorrow is now expected to be worse than originally forecast. The Illawarra/Shoalhaven is now forecast to experience a Catastrophic fire danger, as will Greater Sydney and Greater Hunter. More info here: https://t.co/RQyA5UAi8x#nswrfs#nswfirespic.twitter.com/1xlwByvpMz— NSW RFS (@NSWRFS) November 11, 2019
Emergency Services Minister David Elliott on Monday morning said residents were facing what "could be the most dangerous bushfire week this nation has ever seen".
The NSW fires have claimed three lives and so far destroyed more than 150 homes.
A total fire ban has been declared across the state for all of Monday and Tuesday.
Premier Gladys Berejiklian said the last time a state of emergency was declared in the state was 2013 when there were extensive bushfires in the Blue Mountains.
Ms Berejiklian warned people to "for heaven's sake, stay away from bushland" on Tuesday.
"The catastrophic weather conditions mean that things can change very quickly," she told reporters on Monday.
"You might think you're OK and a few minutes later you won't be. Please heed all the messages you receive. Tomorrow (Tuesday) is not the day to be complacent."
Mr Elliott said the state of emergency was precautionary but necessary.
"We have tools like state of emergency available to us to ensure there is no legal barrier, there are no operational barriers, to ensure that the people of the Rural Fire Service (can) do what they're meant to do," the minister said.
There are currently 60 fires burning across NSW with more than half uncontained.
"Catastrophic is off the conventional scale," RFS Commissioner Shane Fitzsimmons said.
"We are talking about indices that go well beyond the old scale of 100."
The blazes are raging from the northern border with Queensland down to the mid-north coast, out to the state's central west and south toward the Illawarra.
Catastrophic fire danger has been declared for the Sydney and Hunter regions on Tuesday with severe and extreme danger across vast tracts of the rest of the state.
For more on how to prepare a bush fire survival plan, click here.
- with AAP