An emergency warning has been downgraded for a bushfire burning at Castlereagh near Penrith, as weather conditions ease.

Key points: A blaze at Castlereagh near Penrith was briefly at emergency warning level but now at advice level

A blaze at Castlereagh near Penrith was briefly at emergency warning level but now at advice level Residents around Ticker Street, Devlin Road and Richards Road are advised to put their bushfire survival plan into action

Residents around Ticker Street, Devlin Road and Richards Road are advised to put their bushfire survival plan into action Two other fires in northern NSW were also downgraded from watch and act to advice

At least one house and a caravan have been damaged as fire came right up to the front door. It is unknown whether the residence is occupied.

About 100 firefighters had been working at the site, assisted by waterbombing aircraft.

Despite earlier warnings that conditions were easing, the situation was escalated to emergency level about 3:45pm.

The fire was downgraded about one hour later and is now at advice level.

Due to an earlier wind change, conditions fuelled fire activity in the north-western part of the fire, threatening homes.

Earlier, the NSW Rural Fire Service (RFS) said the out-of-control bushfire was burning in Devlin Road in a north-westerly direction towards Tickner Street and Richards Road.

People in areas around Tickner Street, Devlin Road and Richards Road were advised to seek shelter.

Fire crews have been working on the Castlereagh fireground for most of Friday. ( Facebook: NSW RFS )

The RFS said strong south-easterly winds could blow embers ahead of the fire, threatening homes before the main fire front hits.

Residents have been warned by emergency alert text messages.

The forecast for Penrith on Friday was for temperatures of up to 34 degrees with winds reaching 40kph.

Winds were expected to drop to about 15kph later on Friday afternoon, with some light rain forecast which should aid firefighters.

Elsewhere in NSW, watch and act alerts were issued for bushfires burning at Tanilba Bay near Port Stephens, at Red Range, Glenn Innes and Ashby Heights in the Clarence Valley.

However they were later downgraded to advice.