Flash flooding possible in northern NSW

Although residents on NSW's north and mid north coasts have experienced some relief from the persistent rain, the State Emergency Service is still warning of possible flash flooding.

Despite a severe weather warning being cancelled on Tuesday, localised heavy rains still have the potential to cause flash flooding in low-lying areas of the Northern Rivers district, SES spokeswoman Carmel Phillip told AAP.

Locations that may be affected by heavy rainfall on Wednesday include Lismore, Grafton, Coffs Harbour, Byron Bay, Ballina, Casino, Kyogle, Yamba, Maclean, Woolgoolga, Sawtell and Dorrigo.

Minor flood warnings are current for the Orara and Richmond/Wilsons River Valleys.

A wet long weekend saw more than 150 millimetres of rain fall across the Northern Rivers district in 48 hours.

The SES has reminded people to stay out of floodwaters after four people were rescued over the past few days, including an elderly woman whose car slid into a creek and became partially submerged on a property north of Byron Bay.

The 73-year-old woman's head was just above water level before she was rescued by a NSW Volunteer Rescue Association raft, and taken to a Tweed Heads hospital in shock with a fractured leg and hypothermia.