It was initially believed to have been started by an electric fence, however it was later discovered that it was self-combustion of a compost heap.

Central West Police District Chief Inspector Peter Atkins said the fire burnt about two hectares and was extinguished quickly.

Canobolas Zone Rural Fire Service fire mitigation officer Geoff Selwood said the fire came up through a paddock.

"Luckily it was spotted by the owners and they called the RFS very quickly," Mr Selwood said.

He said a call was made to triple zero at 12.26pm and at 1pm firefighters, who had the fire under control were still "blackening it out".

The fire occurred amid worsening conditions across the Central West with low humidity, heat and 40 km/h winds and 57km/h gusts in the Orange area at 1pm.

The Orange region was listed as being at severe risk and a total fire ban is in place.

"Things like this, a little electric fence can cause things to grow," Mr Selwood said.

"We have four strike teams across the area ready to go instantaneous."

Volunteer firefighters from the RFS were also still at JR Richards resource centre on Euchareena Road at Molong at 1pm.

Mr Selwood said there was no fire but an 800-tonne mulch pile combusted so workers were spreading out the mulch so firefighters could cool it.

Mr Selwood urged anyone who sees a fire to ring triple zero.