Total fire bans are in place for Greater Sydney, Greater Hunter, North Coast, New England and Northern Slopes regions, RFS spokesman Brendan Doyle told AAP on Saturday morning.
He said 17 fires were burning out-of-control across the state, with the most serious in the Taree and Great Lakes area on the mid north coast.
He said firefighters had managed to contain the ‘Purfleet fire’, south of Taree, that had so far burnt through about 100 hectares of bush.
He said gusty winds and high temps would test fire containment lines through the day.
‘With today’s weather conditions, they’re going to be tested with the strong winds, so there’s still a lot of work ahead of these firefighters today, tomorrow and the next few days,’ he said.
He said about 500 firefighters would be out battling blazes on Saturday, with hundreds more on stand-by.
The hot, dry and windy conditions forecast meant any new fires that broke out could spread quickly, Mr Doyle added.
‘They can affect homes in a very short timeframe,’ he said.
He said no homes were currently under threat.