NSW Premier Gladys Berejiklian has extended her gratitude to all the emergency workers and NSW firefighters, and said warnings about the severity of this bushfire season had "unfortunately ... come to fruition".
New South Wales Rural Fire Service confirmed on Sunday they were expecting some of the worst fires to erupt on Tuesday.
About 1,000 firefighters are attempting to tackle the blazes in New South Wales, supported by water-bombing aircraft.
"There are significant resources committed to fires and they are limited".
Gusty winds and up to 35C heat have exacerbated the fires, many of which are in drought-affected areas.
In Queensland, thousands of people spent the night in evacuation centres while officials assessed whether it was safe for them to return home.
Meanwhile in Western Australia, one fire was declared at an emergency level on Saturday afternoon and authorities warned of high fire risk throughout the state, the Department of Fire and Emergency Services said.
"The forecast for the balance of the season continues to be driven by above-normal temperatures (and) below-average rainfall to dominate over the coming months", he told Reuters news agency.
The state reports they also received the highest number of emergency-level fire reports in the region.
When asked whether the fires were a wake up call for the federal government to develop proper plans for resourcing to fight fires, Littleproud said the government had been prepared. In some areas, residents were stuck and told to simply "seek shelter as it is too late to leave".
The sun above Lake Hawea as the NSW fires burn.
Emergency services said they had found the remains of one person in a auto and a woman died despite medics struggling for several hours to save her.
MetService says a north-west flow is carrying large plumes of smoke more than 2000 kilometres across the Tasman to this country. But the storms were not almost enough to end the long-running drought.
In Queensland, more than 1,200 firefighters were battling 51 active fires across the state on Sunday, with 39 aircraft deployed to assist for the first time ever in the state.
"We just can not overstate the profound impact that the drought is having on fire behaviour", Mr Fitzsimmons said.
"With rising temperatures and increasingly dry conditions worsening across the State, access to water is essential for survival". In some cases authorities have drilled bores to keep up with demand.
"It is a sobering reminder of what's around the corner", he said.
Mr West said he'd heard from people in the Bobin area who were suffering, as well as unconfirmed reports of property loss.
The poor air quality prompted health warnings for those with asthma and other respiratory problems.
"It's climate change, there's no doubt about it". But this was a dramatic start to what scientists predict will be a tough fire season - with climate change and weather cycles contributing to the unsafe combination of strong winds, high temperatures and dry conditions.
A 69-year-old woman, Vivian Chaplain, died in hospital of severe burns after trying to protect her home, and a man, George Nole, was found inside a burned out vehicle, authorities said. Australia began the year with record-breaking heatwaves, and it looks like it might end the year with devastating wildfires.