Southwest parts of Western Australia are set to see their coolest spell of the year so far as a strong cold front sweeps across the region. The front is approaching the South West Land Divison today and will cross this afternoon and evening, bringing with it much cooler conditions. The front will be accompanied by showers which will amount to a widespread 5-15mm, with some places seeing as much as 30mm. On Monday, many places will see their chilliest day of the year, with Perth heading for a top of 19 degrees, Bunbury 17 degrees and Albany 15 degrees. Blustery southwesterly winds will persist in the wake of the front, making it feel two-to-four degrees colder than the temperature suggests. A ridge of high pressure will push in later on Monday, causing winds to ease significantly and skies to become clearer. This combination of lighter winds and clearer skies will mean most places will experience their coldest night of the year so far, with Perth set to dip to five degrees and Bunbury six degrees. For the remainder of the week, the high will bring a run of cool nights and mornings, but most days will be sunny and mild, reaching the high teens and low 20s across the state's southwest.