More than 4000 people remain isolated in northern NSW because of heavy rain, with more wet weather forecast for much of the state.
Eleven rivers in the northern rivers and mid-north coast regions have flooded, with the Bureau of Meteorology issuing severe thunderstorm warnings on Monday for those areas, along with the central west slopes and plains, and upper western and northern tablelands.
Significant rainfall has eased in those areas but showers will persist this week because of a humid air mass hovering over the state.
The SES says about 4000 residents in the Clarence and Nambucca regions remain isolated, with the majority near Iluka.
New storms forming in the Blue Mountains and northern rivers are being monitored but are not expected to cause problems in populated areas.
Regional residents in Katoomba, Orange, Goulburn, Dubbo, Yass and Parkes were warned of flash flooding on Monday evening following severe storms.
Since the wild weather began last week, the NSW State Emergency Service has responded to more than 3300 jobs, many in Coffs Harbour, Gosford, Hornsby and Sydney's Hills area.
The SES has also carried out 85 flood rescues.
The rain may have eased on Monday, but the SES is warning NSW residents around swollen rivers, especially the Orara and Macintyre rivers, to take care.
"We're asking people not to be complacent with the fact these river systems are starting to drop, there's a lot of water around," SES spokeswoman Sue Pritchard told AAP.
Residents are also being asked to keep clear of stormwater drains after an 11-year-old boy died when he was sucked into one while playing on a bodyboard in a park near Wollongong last week.
"Apart from the contaminants like septic waste and chemicals, along with snakes in the water, there's the real danger of drowning in them," Ms Pritchard said.
"People just think that there are some areas that are relatively safe, but nowhere's safe, and it's not a place for kids to play."
Despite already being saturated for days, rain will also continue to fall in Newcastle, Sydney and the Illawarra.
The capital city has managed to evade the downpour for just three days so far this month.
