The Perth metropolitan area has recorded its coldest May morning for almost 100 years.
The temperature dropped to 1.3 degrees just before 7:00am.
That equals the record low set on 11 May, 1914.
It was even colder in Jandakot, where the mercury dipped to -0.6 degrees.
The duty forecaster at the Bureau of Meteorology Mark Paull says the cold mornings are being caused by a high pressure system to the south of the state.
He says they will continue for the next few days.
© ABC 2012
16:39 EST The mercury soared in the nation's southwest today with Perth recording its hottest September day on record, however heavy rain and cooler temperatures will arrive on Sunday.