A SMOKE alert has been issued thanks to two big prescribed burns being carried out south east of Perth.
The alert includes areas between Two Rocks to Bunbury and the Perth Hills to Harvey.
The Parks and Wildlife Service said smoke from the fires in the Perth hills, 25km south east of Mundaring and 25km south east of Dwellingup, was expected to clear tomorrow afternoon.
Thick smoke also blanketed Perth yesterday.
The Department of Fire and Emergency Services said the burns had been identified as a high priority in order to reduce fuel loads and to protect homes in Mundaring, Sawyers Valley, Chidlow and Dwellingup.