A low pressure trough sitting off the NSW coast continues to dump rain on the state's north and mid-north, with little relief in sight for two days.
A marine wind warning remains in place for much of NSW's north coast on Sunday, while most of the state is under a hazardous surf warning.
The Bureau of Meteorology's Alex Majchrowski said more than 72 millimetres of rain fell in Red Rock on Saturday, and 65mm near Port Macquarie.
But he said minor flood warnings for the Wilsons River, Paroo River (NSW) and Richmond River should ease over the course of Sunday.
"A lot of the weather is due to that low pressure system just sitting to the northwest of Lord Howe Island," Mr Majchrowski said.
"Hazardous surf conditions will persist throughout today and tomorrow before easing on Tuesday, and the rainfall should start to ease from then as well."
Mr Majchrowski also said that a cold front would likely move across NSW late on Monday, with temperatures dropping by about 10C.
Damaging winds would continue on Lord Howe Island until Tuesday.
Meanwhile, across the border, Queenslanders have endured above-average temperatures on Sunday in the state's south and centre.
Brisbane is expected on Sunday to reach a high of 33C while Rockhampton will hit 38C, Longreach 40C and Birdsville 43C. Temperatures will endure across the state's south and centre on Monday and Tuesday.
Residents in the Northern Territory town of Katherine are also on alert after heavy rain pushed a local river to its highest level in four years.
More than 250mm of rain fell in the Katherine River catchment over the past three days, the Bureau of Meteorology reported.
Australian Associated Press
