Perth is on target for its earliest 30 degree spring day on record. Spring is in the air in the nation's west, with the very warm airmass over northern Australia set to be drawn into the west. A particularly strong frontal system is the culprit for the heat, causing northerlies to drag the heat into the western capital ahead of its arrival on Thursday. Tomorrow, Perth is likely to reach an unseasonably toasty 31 degrees. In 119 years of records, Perth's previous earliest 30 degree day in the warming season was the 12th of September, recorded in 1939. From Thursday to Saturday the weather will be fairly wild in the nation's southwest as the first front crosses on Thursday, followed by another pair of fronts traversing on late Friday and Saturday. These will drop the temperature and bring a run of fairly windy days with a series of showers. Calmer weather will finally return on Sunday and Monday, although it will probably be a while before the 30 degree mark is eclipsed again.