It's going to be a cold, wet and windy weekend in southwestern districts of Western Australia, with thunderstorms and small hail likely in some areas.

A cold front will pass over Western Australia's South West Land Division on Friday night and Saturday morning, bridging a burst of showers and cold, blustery winds. 

Image: Forecast surface wind speed and direction on Saturday afternoon, according to the ECMWF model.

Behind the front, showers and gusty winds will persist through Saturday and Sunday as a complex low pressure system passes to the south of the state. The cold air being driven north by this low could cause thunderstorms and small hail over parts of the state's southwest on Saturday and Sunday, including Perth.

A sheep graziers warning has been issued for the Lower West, South West, South Coastal, South East Coastal, Great Southern and Central Wheat Belt forecast districts on Saturday. More weather alerts may come out over the weekend.

After reaching 23 degrees on Friday, Perth is only forecast to hit 19 degrees on Saturday and 17 on Sunday. This would be the city's coldest weekend since mid-July.