Widespread blackouts have swept through southern WA as light rain and humidity damaged 100 poles and sparked around 50 pole top fires.
At its peak, more than 50,000 homes were left without power. Western Power has restored nearly half but about 21,000 properties are still without electricity.
Among those affected is Swan Christian College, which experienced a complete power outage.
College administrators have told its 1500 students not to turn up to school today because it was unknown when power could be restored.
“When we have misty and/or humid conditions — generally along the coast or light drizzling rain — this can combine with dust and pollution and create a paths or “tracks” on the insulators which lets electricity jump across,” a Western Power spokeswoman said.
“Around 50,000 homes and businesses were affected overnight with around 27,000 being restored by back-feeding power around the damaged sections of the network.”
Scattered outages are affecting residents from north of Geraldton to Bunbury, including the Perth metropolitan area.
As of 7.45am, the most affected suburbs are Thornlie, Canning Vale, Wandi, Trigg and Spearwood.
Main Roads WA has warned motorists to drive with extreme caution as traffic signals are blacked out in various suburbs throughout the city.
The spokeswoman said planned work had been cancelled and extra crews called in to restore electricity. The aim was for power to be restored by the end of the day.