The Perth metropolitan area has recorded its coldest morning of the year.
The temperature dropped to 0.4 degrees just before 6:30 am.
That is the coldest temperature recorded in Perth since July 3, 2010 when the mercury dipped to 0.3 degrees.
It has been even colder at Jandakot which has recorded minus 1.6 degrees.
One commuter reported scraping frost off the windscreen before being able to drive in.
The cold did not stop regular early morning swimmers at Cottesloe beach from taking a dip.
School teacher Colin Murphy says after swimming most mornings for 20 years he hardly notices it.
"I didn't know it was the coldest morning of the year, but I went down to North Cott and swam from Grant Street back to the Blue Duck," he said.
"The wind's worst than the cold really, that's ok, it's a good way to start the day."
The coldest regional centre is Northam where the temperature dipped to minus 4.3 degrees.
The duty forecaster at the Bureau of Meteorology says a ridge of high pressure, combined with clear skies and light winds, is causing the low temperatures.
He says the cold mornings will continue for the rest of the week with forecasts of 2 degrees for Thursday, 4 for Friday and 5 for Saturday.
© ABC 2012
07:18 EST Fog has been blanketing parts of southeastern Australia this morning, including the Adelaide and Canberra areas, affecting road and air traffic.