Calm winds keep NSW bushfire in control

Winds remain relatively calm in the NSW Blue Mountains where firefighters are still working to control a bushfire.

The Wentworth Falls blaze is not posing any immediate threat to homes along Coronation Rd after light rain overnight.

Earlier on Monday RFS Deputy Commissioner Rob Rogers said crews were bracing for stronger winds, with gusts of 40-60km/h, which could have caused the fire to flare up.

"Wind speeds are nowhere near the speeds of yesterday and should maintain this current speed for the next few days," an RFS spokesman told AAP just after midday.

No extra precautionary measures are needed for now, he said.

The fire, which threatened about 40 homes at the weekend, has now burned more than 350 hectares in the area around Tableland Road, Little Switzerland Drive and Hordern Road.

The cause of the bushfire is not yet known but it is being treated as suspicious.