A fifth person has died in a region devastated by floods after dangerous conditions prevented emergency crews from accessing a home.

The body of a man believed to be his 80s was found inside a burnt-out vehicle in the shed of a Cooplacurripa property, about 50km north-west of Taree on the NSW mid-north coast.

A concern for welfare had been raised on Wednesday after the shed was reportedly spotted alight but severe weather conditions prevented crews from getting to the property by road.

Access to the home was only possible by helicopter with officers arriving early on Friday afternoon, NSW Police said.

The intense rainfall that has battered the mid-north coast for several days moved south on Friday, but communities remain cut off and it will take some time to recover once floodwaters recede.

Prime Minister Anthony Albanese and Premier Chris Minns planned to visit hard-hit Taree but their attempt to meet affected locals was aborted, further highlighting the town's isolation by its second major flood in four years.

But their attempt to meet affected locals was aborted, further highlighting the town's isolation by its second major flood in four years.

"Conditions in Taree are very tough," Minns said from Maitland.

"We've heard word from local MPs and businesses that they've had a torrid three days, incredibly difficult circumstances.

"We know it will take a long time to get that community back up on its feet."

Port Macquarie local Margret Meagher said the town took 18 months to recover from its last major flood and it would be important for the community to band together.

"People feel they're isolated, so that's where the whole community spirit is so pivotal," she said.

More than 1600 insurance claims have already been made, according to the Insurance Council of Australia.

"Insurers stand ready to serve customers through the oncoming recovery period," chief executive Andrew Hall said.

Four people have died and hundreds of residents rescued as floods wreak havoc. – AAP

Of the five deaths linked to the record-breaking floods, three have involved drivers.

The body of a man in his late 70s was found on Friday after his vehicle appeared to be swept off a causeway at Nana Glen near Coffs Harbour.

Another man died at a flooded home near Taree, as did a driver west of Port Macquarie and a 60-year-old woman near Coffs Harbour.

A man missing in Nymboida has been located but police have not ruled out floods as a factor in the disappearance of another man in Bellingen.

But hundreds of people would be dead without SES volunteers, the premier said.

"We're in deep, deep gratitude to those people," Minns said.

The prime minister announced personal hardship assistance grants of $180 per person or $900 for a family would roll out in coming days.

Those unable to work in the hardest-hit areas will be able access a disaster recovery allowance from Monday afternoon.

"Tragically, we're seeing more extreme weather events. They're occurring more frequently and they're more intense," Albanese said.

There had been more than 675 flood rescues, including 177 in the 24 hours to 5am on Friday, the SES said.

But with the rate of flood rescue requests decreasing, the SES is focusing on getting supplies to the 50,000 people still isolated by floodwaters.

Emergency workers wade through floodwaters as they prepare inflatable boats to effect rescues near Taree. – AP

Locals in Port Macquarie also took things into their own hands, boating food to people in the city's northern suburbs.

The slow-moving trough that dumped months of rain over the mid-north coast has shifted south, bringing heavy falls to the Hunter, Blue Mountains, Sydney and Southern Highlands.

Drier conditions are forecast in the flood-ridden areas but residents are not out of danger.

"There are waters still moving quite quickly through the river systems, a lot of debris around so it's quite dangerous," Bureau of Meteorology's Jane Golding said.

Increased wind on Monday and Tuesday could also uproot trees and buildings from sodden soil.

The SES had 167 warnings in place on Friday afternoon, with low-lying parts of Sydney also warned to prepare for evacuations.

Police also warned drivers in metropolitan Sydney to exercise caution in wet weather after two deaths overnight – including a 95-year-old hit by a car in Liverpool.

Disaster assistance from the state and commonwealth governments has been expanded, with 19 areas now eligible for support.

Flooding at Port Macquarie. – AAP

Floods submerge towns and isolate communities

What has caused the flooding?

• A low-pressure system over the NSW mid-north coast has dumped months of rain over a few days
• Catchments were already saturated, with year-to-date totals before this week already topping 1000mm (39.3 inches) in Port Macquarie and 690mm (27.1in) in Taree 
• Taree's Manning River is falling after reaching a record height of 6.45m, while the levee has been overtopped in Kempsey, population 30,000

Which communities are impacted?

• Emergency warnings are active in 40 areas including Croki, Macksville, Dungog, Kempsey, Port Macquarie, Nambucca, Taree, Wingham, Bowraville and Gloucester
• More than 48,000 people are isolated due to floodwaters
• Disaster assistance has been activated in 16 local government areas 
• Advice warnings have been issued in some areas around the Nepean River on Sydney's fringes
• Two men have died – one at Moto north of Taree, the other at Rosewood near Port Macquarie
• At least two other people are missing – a 60-year-old woman in Dorrigo and a 49-year-old man in Nymboida believed to have walked into flood waters
• More than 524mm (20.6in) of rain has fallen in Taree, 411mm (16.1in) at Port Macquarie and 371mm (14.6in) at Kempsey since Monday

What services have been affected?

• Several town centres are underwater
• 700 households and businesses without power
• 181 schools are not operating or under minimal supervision, along with 102 childcare centres
• Scores of livestock have been washed down rivers, with survivors ending up on beaches and in town centres
• Evacuation centres have been set up at Bellingen, Dungog, Gloucester, Taree, Manning Point, Wingham, Bulahdelah, Tuncurry Beach, Kempsey, Port Macquarie, Coffs Harbour, Nambucca, Old Bar, Wauchope and Coopernook

What's next?

• Moderate rainfall is expected on the mid-north coast as the system moves south
• Sydney's Nepean Dam is currently spilling and the Warragamba Dam is expected to spill sometime on Friday or Saturday.
• Between 60 and 100mm of rain is forecast over the Sydney and Blue Mountains region in next 24 hours
• Heavy rain is expected in Newcastle, Central Coast, Southern Tablelands, Snowy Mountains, Illawarra and South Coast on Friday
• Rain is expected to move south and shift off the NSW South Coast on Saturday morning
• Cold and windy conditions next week could bring more havoc, felling trees in wet ground