A SMOKE alert has been issued for the northern suburbs this afternoon.
The Parks and Wildlife Service at the Department of Biodiversity, Conservation and Attractions issued the alert for suburbs from Yanchep to Hillarys about 1.50pm.
The smoke is from a prescribed burn being carried out by the department in Pinjar Pines today and is expected to clear overnight.
People shut doors and windows and turn off air-conditioners if smoke is thick.
Smoke may reduce visibility on some roads and motorists are urged to take care, turn on headlights and travel at appropriate speeds through affected areas.
People with asthma and pre-existing respiratory or cardiovascular illnesses should follow their pre-prepared treatment plan.
People with conditions exacerbated by smoke should take precautions in line with their medical advice for these circumstances.
There are also prescribed burns east of Yanchep and Two Rocks today.
Visit www.emergency.wa.gov.au, call 13 DFES (13 3337) for updates.