Tropical Cyclone Nancy crossed the coast in New South Wales at Byron Bay and moved seawards which brought about high winds and heavy rainfall. Subsequent flooding affected rivers in the central and south-east regions including the Albert, Nerang, Logan, Paroo, Bulloo and Mary. Reports stipulated some areas received 530 mm of rain over a 24 hour period.

There was extensive damage to infrastructure including houses, roads and buildings as a result of cyclonic winds that recorded wind gusts of up to 60 - 70 knots.

Cyclone Nancy dumped a large amount of rain on Newcastle, which increased the rate of movement in some structures and prompted the discovery of leaks in buildings that had previously been considered structurally sound after the December 1989 earthquake.

The Insurance Council of Australia estimated the 1990 damage caused by Cyclone Nancy at $33 million, with the 2011 estimated normalised cost of $197 million.