A severe weather warning has been issued for WA's South West, with winds of up to 100 kilometres per hour, thunderstorms and possible hail expected, following a weekend of heavy rain which has been welcomed by farmers.

Key points: Perth is bracing for its third cold front in as many days

Perth is bracing for its third cold front in as many days Wild weather and erosion has forced the closure of Fremantle's Port Beach

Wild weather and erosion has forced the closure of Fremantle's Port Beach Authorities are warning of possible damage to homes and property across the South West

The warning covers areas of the South West from Jurien Bay to Hopetoun.

A cold front will sweep across the area — the third in as many days — with winds and rain expected to lash the coast late on Sunday and during Monday. Storm conditions are forecast to peak around midday on Monday for Perth.

Up to 30 millimetres of rain could fall in coastal areas between late Sunday and early Tuesday.

The Bureau of Meteorology said the cold front would bring winds of up to 100 kilometres an hour which could cause damage to homes and property along the south coast.

Residents are advised to take action where possible, including staying away from trees, powerlines, storm and streams, the Department of Fire and Emergency Services said in a statement.

Cottesloe Beach has been impacted by weekend storms. ( ABC News: Robert Koenig-Luck )

People are also urged to avoid driving in flooding and stay indoors.

On Thursday night the region received more rainfall in a 24-hour period than in the whole month of May.

Margaret River recorded 88mm of rain while 28.4mm was recorded in Perth, the wettest June day in two years.

Farmers welcome rainfall

Bureau of Meteorology forecaster Neil Bennett said the rain was essential as farmers had experienced their driest start to the year since 1900.

"The problem has been that it's been so dry that the soil is so dry that the rain itself needs to fall for another few weeks at least to make substantial differences to the subsoil, but they'll take anything they can right now given the fact that it's been so dry," Mr Bennett said.

WA Farmers president Rhys Turton said the expected heavy rainfall was badly needed by the state's agriculture industry.

"It's been a shockingly dry autumn and a terribly dry start to winter for pretty much all of the farming regions in the south west land division so this has been a relief," Mr Turton said.

"I just hope it's been very widespread and most certainly gives us some hope going forward.

"If we receive any sort of double digit rainfall figures out of this, it'll probably mean the difference between getting some livestock feed and some crops and not getting anything at all."

Fremantle's Port Beach closed

Hazardous surf is expected to continue in the week along the west and south coasts as a result of strong winds and large swells.

The conditions are causing erosion at of some of Perth's most popular beaches, including Fremantle's Port Beach, which has been closed indefinitely, while Cottesloe has also experienced erosion.

Fremantle mayor Brad Pettit said Port Beach may not reopen for several weeks.

Port Beach in Fremantle is closed after storms caused beach erosion. ( ABC News: David Weber )

"It really depends largely on the natural processes around some of that sand replenishment and we'll do some stabilisation works ourselves and also future storms are part of the challenges there," he said.

Mr Pettit said the council was considering bringing in sand and installing protective barriers under sand dunes and sea walls to help tackle the problem.

"The real challenge is of course that this is a problem that's going to continue to get worse over coming decades, so we're really just looking for not just a short-term fix but a long-term solution to this problem," Mr Pettit said.

Fremantle resident Kathleen McDermott said it was disappointing there had been so much coastal damage.

"In all the years I've lived in Fremantle I've never seen the beach this far up ... the tide so far up there's absolutely no beach left," she said.

"We're right up against the rockpool and all the sand dunes are gone, so it's a bit disappointing to see it eroded away.

"It is a danger if anyone does come to swim so I can understand them closing the beach off."