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).

Although no fatalities resulted from Joan, the cyclone caused widespread destruction across areas of Western Australia.

Cyclone Joan originated from a mass of convection that formed northwest of Darwin on 30 November 1975.

[2] On the next day, the forward motion of the storm slowed as while it passed to the north of Rowley Shoals, before abruptly turning towards the south, toward the Australian coast.

[2][4] Heading towards the south, Joan made landfall near Mundabullangana, Western Australia late on 7 December with winds of 220 km/h (140 mph) and an estimated pressure of 915 hPa (mbar; 27.02 inHg).

[3][4] After making landfall, the cyclone steadily weakened over land as it passed over areas of Western Australia.

[1] However, after crossing the Hamersley Range on 8 December, Joan began a phase a rapid weakening, and by the end of the day, its maximum sustained wind was only 100 km/h (62 mph).

The most severe type, the second cyclone warning phase, began to be initiated in three hour intervals beginning on 6 December after Joan made an abrupt turn towards the south.