UPDATE: A bushfire watch and act alert has been issued for residents in Wandowie and Wooroloo east of Perth as a blaze threatens.
The alert was issued at 12.35pm (WST) today, with residents in the affected areas in the Shires of Northam and Mundaring warned to leave or get ready to actively defend their properties.
The bushfire's moving slowly in a northwesterly direction.
Some roads have been closed and power has been cut in some areas.
Meanwhile, firefighters have saved about 30 homes and nearby pastures in Western Australia's southwest.
Firefighters are battling the blaze in high winds and soaring temperatures.
A bushfire emergency warning was downgraded early today to a watch and act alert for residents of the Wannamal township and surrounding areas just north of Perth.
The Fire and Emergency Services Authority said the running fire has been stopped and the blaze is 85 per cent contained but could still pose a threat in the high winds.
About 100 firefighters are at the scene and are strengthening containment lines.
Two other fire near Margaret River, south of Perth, have also been contained.