Smoke has covered suburbs between Jarrahdale and Armadale today following a planned fire.
The Department of Biodiversity, Conservation and Attractions have reported burn offs in the southerns suburb of Karrakup between Armadale and Jarrahdale, and Roleystone today.
The smoke was expected to be visible until the morning of October 6.
DBCA advised closing doors and windows, and turning off air conditioners if smoke was particularly thick.
Motorists should take extra care on the road, drive at appropriate speeds and turn on headlights while travelling in areas with heavier smoke.
People with asthma and pre-existing respiratory or cardiovascular illnesses were advised to act according to healthcare professional recommendations.