Perth had been on track to have its second driest June on record, but has now had its wettest June day in 31 years, the Bureau of Metereology says.
The city had received more than 60mm of rain by Thursday morning, with more showers expected in the afternoon and through to Friday before skies cleared over the weekend, weather bureau spokesman Neil Bennett said.
There has been a low pressure system over the southern half of WA, although Wednesday night's rainfall failed to sate agricultural areas, where farmers predicting a poor grain harvest are yet to receive any decent rain.
Perth has had one of the warmest and driest starts to winter in recorded history, with temperatures averaging 23C for the first two weeks of winter and 26mm of rain, with 172mm the average for the month.
