Over the past few days Western Australia's southwest has endured a series of rain-bearing systems with the mercury also dropping. Gingin picked up 44mm in the 24 hou8rs to 9am Tuesday, making it the heaviest April rain they have seen in over 20 years. At Merredin in the Central Wheatbelt, the 29mm received during the same period was the heaviest April rain in a decade. With over 53mm recorded so far this month, it has also be the wettest April month since 2002. To 9am Wednesday the heaviest of the falls were focused around the Southern Coastal and the Southwest, with Albany steadily gaining 17mm during yesterday evening and overnight. The recent rain has helped many districts achieve at least their average April rainfall. Some places in the Central West, Lower West and South West have now seen two-to-three times the April average rainfall. For some it has been the wettest start to the season in over a decade. As the skies began to clear over the southwest, the cold to set in. Overnight, the temperatures plummeted. Perth cooled to 10 degrees, seven degrees colder than the previous night. Much of the Southern Coastal district chilled below 10 degrees this morning. It was also a chilly morning in some of the surrounding districts, including the Lower West, Southwest and Great Southern. Most places were between three-to-six degrees colder than the April average this morning. During the next week, several cold fronts look to sweep over the southern parts of WA in rapid succession. This will see days stay much cooler than average, with Perth likely to remain in the low-20's with a shower possible each day.