Western Australia's South West has been lashed by heavy rain and strong winds, with a cold front blanketing the mountain peaks of the Stirling Range in snow.

Key points: Snow only usually falls on WA's Stirling Range a few times a year

Snow only usually falls on WA's Stirling Range a few times a year The falls are far smaller than in other parts of the country but people have hiked up to see the snow

The falls are far smaller than in other parts of the country but people have hiked up to see the snow Strong winds and rain also lashed Perth overnight, bringing down debris on roads

A severe weather warning was in place on Friday night for the Goldfields-Midlands, Perth metropolitan area and the South West.

"We had a strong cold front move through overnight followed by a cold, unstable airmass," Bureau of Meteorology (BOM) senior forecaster Adam Conroy said.

"There was some reasonably strong winds recorded."

The strongest wind gusts recorded by the BOM were at Ocean Reef, where they reached up to 107kph, while other sites along the south-west coast felts gusts of up to 100kph.

The heaviest rainfall for the area was 47 millimetres, recorded in the Perth Hills.

"Areas south-west [of the] line from Albany to Lancelin had falls in the range of 15 to 30 millimetres from the system, and up in the Perth Hills we had some even higher falls," Mr Conroy said.

The State Emergency Service received 40 calls from people reporting damage to homes overnight.

A tree fell across Marmion Avenue amid strong winds. ( ABC News )

There was debris on roads, including on Marmion Avenue in Kinross, where a tree blocked the road completely.

The cold temperatures were expected to linger throughout the morning.

"The conditions are reasonably cold with this system so we're expecting only a top of around 15 [degrees Celsius] in Perth today, and that's the sort of temperature we probably see only a few times in Perth this winter," the forecaster said.

Snow dusts southern peak

Tiny snowmen dotted the top of Bluff Knoll after the snowfall. ( ABC News: Jack Schmidt )

The icy blast saw a dusting of snow on the Stirling Range in the early hours of Saturday morning, one of the few places in WA where moderate amounts do occasionally fall.

Some snow chasers drove hours to see the sight.

The range's highest peak, Bluff Knoll, records a few snowfalls each year and dozens of people trekked up the mountain for a glimpse of the latest snow.

A snowman on top of Bluff Knoll. ( ABC News: Jack Schmidt )

Gavin Jackson also ventured out to see the snow.

"Climbing up here like every mad person up here trying to catch snow and the freezing cold," he said.

"It's fairly windy, there's heaps of snow falling as we speak, lots of snow setting on the rocks and the grass and trees."

Scott O'Callahan camped in the carpark overnight.

"We're a bit cold but we're happy to see snow up here. It's first time the children have seen snow so it's great," he said.

Claire O'Callahan also said it was very cold.

"Really amazing, worth coming up, I brought socks to put on my hands because I didn't have gloves," she said.