Update: 8pm Residents have been advised to stay indoors because of concerns that expected strong winds could reignite a blaze in the northern part of Glen Forrest.
The cause of the fire that started at about 2pm near Hardey Road is unknown.
Flames were reportedly 20m high and 30ha has been burnt.
By 8pm, the fire was under control. A dozen crews remained to consolidate containment lines.
Residents were advised to stay indoors because of concern that expected strong winds could reignite the blaze.
DFES said there was no threat to lives or homes.
Roads have been reopened in the area but local traffic will only be allowed on the following roads;
Glen Forrest Drive between Ryecroft and Hardey roads, and Hardey Road between Moray and Morrell roads in the Shire of Mundaring.
Glen Forrest Primary School on nearby Tillbrook Street went into lockdown.
Students who attend the primary school have all now been picked up from Morgan John Morgan Reserve in Glen Forrest.
A bushfire advice has been issued for people in an area bounded by Glenburn Road, Hardey Road, Quarry Court, Glen Forrest Drive, Ryecroft Road and Duffield Road.
Although there is no immediate danger for people in these areas, you need to be aware and keep up to date.
Career Fire and Rescue Service, Volunteer Fire and Rescue Service, Bush Fire Service and Department of Environment and Conservation firefighters are on the scene.
The Aircrane, three helitacs, two fixed wing water bombers and the Air Intelligence Helicopter are assisting ground crews.
WA Police are also in attendance.