Perth hills bushfire warning downgraded

"There is a possible threat to lives and homes as a fire is approaching in the area and conditions are changing," the updated warning issued on Wednesday afternoon said.

An earlier emergency warning had instructed residents in the path of a bushfire to leave, with homes under threat.

The fire started near the intersection of Sultana Road West and Smokebush Place east of the airport.

Perth has endured a week of scorching temperatures, with the airport area reaching 39.5C at about 1pm on Wednesday. 

The fire comes two days after another blaze destroyed a home in the Chidlow area, about 40km to the east.