Blaze brought under control after destroying WA homes

Seven emergency-level bushfires have engulfed homes and torn through bushland, rural properties and suburbs on Perth's fringes in the past three days.

Authorities confirmed two more homes had been lost while crews battled a fire at Keysbrook, south of Perth. Both were believed to be empty.

The fire was burning at watch-and-act level before being downgraded on Saturday evening, though an advice warning remains for parts of Keysbrook, Nambeelup and North Dandalup.

Residents were told to remain vigilant and stay up to date with the latest warnings.

"Weather conditions over the next few days will put pressure on containment lines, potentially increasing fire activity in the area," the alert reads.

Department of Fire and Emergency Services incident controller Russell Wells said crews were rotated on Saturday to allow firefighters time to rest.

Resources were bolstered for the evening, he said.

Difficult terrain and homes spread out across a wide area were proving challenging for ground crews, with aerial assets used to spot fires and determine the best place to deploy resources.

In the state's southwest, parts of Callcup, Crowea and Meerup also remained on high alert amid a watch and act notice as crews worked to contain the fireground.

Heatwave conditions in some parts of the state are waning, with the worst of the extreme heat now pushing into the Northern Territory.

But the weather bureau said there will still be severe heatwave warnings in place for WA for a while to come.

"Severe heatwave conditions over much of northern and central WA continuing into next week," the bureau warned.

"Locations likely to be impacted include Kununurra, Marble Bar, Newman and Wyndham."

High fire danger ratings have been forecast on Sunday for 38 districts across the state, the third highest classification.

The fire danger level is expected to rise to extreme in Brockman and Swan Inland North on Christmas Day.

Australian Associated Press