A smoke alert has been issued for areas between Preston Beach, Australind, Brunswick Junction and Harvey in the South West.
The Parks and Wildlife Service at the Department of Biodiversity, Conservation and Attractions has issued the alert. The smoke is from a prescribed burn being carried out 20km south of Collie.
It is expected to clear overnight.
If the smoke is particularly thick, it is recommended people shut doors and windows and turn off air-conditioners.
Smoke may reduce visibility on some roads and motorists should take care, turn on headlights and travel at appropriate speeds when travelling in these 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.
For more information visit emergency.wa.gov.au or call 13 DFES (13 3337).