More than 200 firefighters are taking advantage of a drop in wind strength and temperatures to redouble efforts to control two fires on the New South Wales central coast.

The bushfire emergency warning for Pretty Beach and Lobster Beach has been lifted, but efforts to control another fire at Wyee are still continuing.

The fires threatened homes in beach suburbs of Gosford and properties near Wyee earlier on Friday.

The fire near Wyee had reignited during the afternoon in hot, gusty conditions, breaking containment lines and jumping several roads.

It threatened several homes and also forced the closure of the Sydney to Newcastle train line and put coal mining infrastructure at risk.

The Rural Fire Service's Anthony Clark says while temperatures have dropped significantly, there is still work to be done.

RFS deputy commissioner Rob Rogers says crews are also trying to protect a large coal conveyer belt.

"The fire is basically burning up against the clearing that runs through, and obviously fire crews are doing their best to protect that infrastructure," he said.

Summerhayes Road resident, Ian, says it has been a hectic situation.

"[There was] lots of smoke, lots of firies running around and people having a bit of a look," he said.

"The wind is blowing it everywhere."

Pretty Beach fire

Smoke rises from the bushfire burning between Pretty Beach and Lobster Beach. ( ABC News )

The Rural Fire Service (RFS) says it was touch and go during the extreme conditions at Pretty Beach and Lobster Beach, but the emergency warning is now over.

Commissioner Shane Fitzsimmons says work in rugged terrain in the dark is still challenging.

"There is literally kilometres and kilometres of fire edge that's coming down adjacent to all the homes in and around this valley system," he said.

Around 110 firefighters and several water bombing helicopters have been working into the night to control the blaze, which had been burning all day on Friday.

The bushfire expanded from just 10 hectares to 90 hectares in half a day.

The RFS's Mr Clark says firefighters and volunteers have worked hard.

"Some of our crews up there have been saying it was touch and go there," he said.

"It was looking for a while like we were going to lose some homes but fortunately the crews got in there, they got to work and actually saved those properties.

"There's been a lot of great saves in that area today, fortunately no homes destroyed. A couple of timber decks have been damaged by the fire but fortunately no properties lost."

Efforts praised

NSW Emergency Services Minister Mike Gallagher says many people might be breathing a little easier as result of Friday's efforts.

"People no matter where you are in this state need to look at the experience of today and realise that you have got a threat," he said.

"The threat is not months away. The threat is around us now.

"People do need to heed the warnings of Fire and Rescue and the Rural Fire Service and have a look around at the risks around their homes and property."

Residents in northern Sydney around Ingleside and Wahroonga have been told not to worry this evening if they see smoke and fire.

The Rural Fire Service has decided to take advantage of the cooler weather on Friday night to do a hazard reduction burn.