Australia has entered the first day of 2020 in a state of emergency with more than 100 bushfires still burning and power outages plaguing the devastated south coast.

Military aircraft and vessels are continuing to assist emergency services on Wednesday in New South Wales and Victoria.

This year's bushfire season has claimed 12 lives, and five people are still missing.

The New South Wales town of Cobargo, where a father and son died on Monday bravely battling to defend their homes, has been leveled.

Commissioner of the NSW Rural Fire Service Shane Fitzsimmons said there were 'literally thousands of people taking refuge on the beaches' after being trapped by blazes.

A gusty cool change is expected to wreak further havoc across the state's fatal firegrounds.

Fire conditions are expected to ease on Wednesday after a cool change, bringing gusts of up to 80km/h and dry lightning strikes, crossed the state.

Before 7am no fires were at emergency warning level, but eight - including the 230,000-hectare Currowan blaze on the south coast and the 64,000ha Clyde Mountain fire ringing Batemans Bay - were at watch and act level.

Mallacoota mother Allison Marion took a photo of her son (pictured) wearing a facemask in a boat on the Mallacoota lake trying to stay safe from fire

In apocalyptic scenes, families spent New Year's Eve on the pier in Mallacoota (pictured) after being forced to flee

In Victoria's East Gippsland, a popular holiday destination, 33 fires are still burning and 43 properties have been destroyed.

After a day sheltering on the beach, tourists and locals in Mallacoota spent the night sleeping in a local cinema.

Many spent New Year's Eve on the town's jetty and were told to be ready to get in the water at a moment's notice to keep safe.

Those in the NSW holiday towns of Bateman's Bay and Bermagui also fled to evacuation centres or the beaches on Tuesday.

A telecommunications outage left families unable to contact loved ones in fire-ravaged areas.

'No communication is a rarity in today's world so it's an uncomfortable feeling,' Melbourne man Nic Baxter told AAP on Tuesday evening, as he waited to hear from his father in Batemans Bay.

The Victorian town of Mallacoota (pictured) has no power or running water as families face an uncertain future

'Fortunately, he is located in an area where I'm sure he is OK, but still very uncomfortable.

'I don't think I can celebrate NYE to be honest, too much on my mind thinking about the fires and family.'

NSW Police earlier confirmed all power had been lost from South Nowra to Moruya and 'potentially beyond', affecting at least 46,000 people and the supported telecoms network.

Army Blackhawk and Chinook helicopters were deployed to rescue thousands stranded on a beach in the fire-ravaged area.

US and Canada are understood to have been asked to provide 'specialist aviation resources' to help Australia's emergency efforts.

On Tuesday Scott Morrison said the challenge posed by the bushfire crisis will remain into the new year but hailed the 'amazing spirit of Australians'.

In his New Year's message he said: 'I wish we had better news on New Year's Eve.

'But one news we can always take comfort in is the amazing spirit of Australians.

'We have faced these disasters before and we have prevailed, we have overcome.'

Sydney was criticised for going ahead with its $6.5 million fireworks extravaganza, with many deeming it 'inappropriate' and 'selfish'.

Thousands had signed a petition for it to be cancelled, while NSW Deputy Premier John Barilaro called for funds to be redirected to drought and bushfire relief.

Dozens of homes and a school have been lost in the Victorian towns of Buchan and Sarsfield, with more people missing in the state.

Back in NSW, swathes of the south coast has left 300 Shoalhaven residents living in the Ulladulla Civic Centre.

Waterbombing aircraft helped efforts to stop a 250ha blaze reaching residential homes at Blue Haven on the Central Coast.

Sydney's controversial firework display (pictured) rung in the new year despite calls for it to be cancelled because of the bushfires

Patrick Salway, 29, (pictured with his pregnant wife Renee) died fighting the fires with his father Robert Salway

'We'll have more conscience flights up ... along with the extraordinary firefighting effort,' NSW Rural Fire Service Commissioner Shane Fitzsimmons told reporters on Tuesday afternoon.

'We are truly grateful and appreciative for all everyone is doing.

'We've seen a very responsive, very decisive community understanding and accepting an extraordinary level of disruption from what is proving to be some very destructive and deadly bushfires.'

Total fire bans are in place for Southern Slopes, Southern Ranges and Central Ranges on Wednesday, ahead of predicted worsening conditions over the weekend.

Multiple property losses are likely but it will take several days to assess all the losses, the RFS says.

The towns of Fishermans Paradise, Broulee and Mogo, which is home to a popular zoo, have experienced significant damage.

Meanwhile major roads, including several parts of the Princes Highway linking south coast communities, are likely to remain closed for some time due to hazards.

Premier Gladys Berejiklian is expected to visit south coast communities on Wednesday after receiving a briefing at RFS headquarters.

Bereaved widow Renee Salway took to social media on Tuesday (pictured) and said she is 'broken'. 'I love you now, I love you still, I always have and I always will,' she wrote

The town of Cobargo (pictured) where Patrick and Robert Salway died protecting their home from the bushfire

Cobargo (pictured) has been left devastated by the bushfires, which leveled the town and killed two people

Nearby, the Princes Highway is still closed from Falls Creek to Milton, cutting off huge areas of the coast.

Dairy farmer Patrick Salway, 29, and his father Robert, 63, died trying to defend their home from bushfires in Cobargo in the south east of NSW.

Mr Salway was expecting a second child with his pregnant wife Renee, who paid tribute to her husband on Tuesday night, telling friends she was 'broken'.

'I love you now, I love you still, I always have and I always will,' she wrote.

'I will see you again Patrick, my best friend. Hope you are up there 'fixing things in the stars tonight'.'

It comes as firefighters are bracing for some of the worst conditions yet, with fires spreading 'faster and faster' than experts thought possible.

NSW premier Gladys Berejiklian said a third person was still missing and there were 'grave concerns for their safety'.

The afternoon sky glows orange from bushfires in the area around the town of Nowra (pictured) on New Year's Eve

Fires have devastated the town of Sussex Inlet (pictured) after a hellish New Year's Eve

NSW Rural Fire Service firefighter Samuel McPaul (pictured) was killed at the Green Valley Fire

Samuel McPaul (pictured with his wife) was expecting his first child but was tragically killed in a truck accident

NSW Rural Fire Service volunteer Samuel McPaul also lost his life after the firetruck he was travelling in was lifted from the ground by a 'fire tornado', which flipped the truck on its roof and trapped the three volunteer firemen inside.

The newlywed was expecting his first child.

Meanwhile, incredible footage emerged of a NSW Fire and Rescue crew were dramatically shielded themselves inside a truck after it was encircled by a raging inferno.

In the heart-stopping footage, flames are seen blowing around the truck with the brave firefighters trapped inside.

New Year's Day will see thousands of people still cut off on the roads, with police issuing a stark warning about the current closures.

'The bush fires continue to have a major impact on many roads in NSW,' the warning read.

'The Princes Highway from South Nowra to Milton is closed. The road has suffered significant damage and many trees are down in the area.

'If deemed safe to do so, arborists will work in the area tomorrow in an effort to make the area safe and open the road, however this work is expected to take considerable time.'

Around 30,000 tourists as well as 45,000 locals were told to leave the East Gippsland region on Sunday in what was poised to be one of the biggest mass evacuations in Australia's history.

A helicopter (pictured) is seen fighting a bushfire near Bairnsdale in Victoria's East Gippsland region on New Year's Eve