Severe Tropical Cyclone Joan was an intense tropical cyclone that ravaged areas of Western Australia. Forming out of a tropical low on 30 November 1975, Joan gradually intensified as it tracked towards the west. After attaining Category 5 intensity on 5 December, the storm abruptly began to track southward and accelerated. The following day, the cyclone reached its peak intensity with winds of 215 km/h (130 mph) and a barometric pressure of 915 hPa (27.02 inHg). Joan only weakened slightly before making landfall in the vicinity of Mundabullagana. The cyclone rapidly weakened after landfall before dissipating over Western Australia on 12 December.