Firefighters in New South Wales are stretched thin as blazes continue to spark across the state.
Temperatures were expected to drop on Wednesday and Thursday, but fire chiefs warn dangerous conditions will return later in the week.
The fires have claimed three lives and destroyed at least 170 homes.
- Australia bushfire catastrophe puts more lives at risk
- Australia fires: Motion map shows smoke hitting New Zealand on Wednesday
What you need to know:
- Three people have died and more than 200 homes damaged or destroyed
- A state of emergency has been declared in New South Wales
- As of Wednesday morning 73 fires were burning across NSW
- New Zealand firefighters have been sent to help contain the fires
- Temperatures have dropped, but more dangerous conditions are likely later in the week.
These live updates have now ended. More on Newshub at 4:30pm, 6pm and at newshub.co.nz
1:32pm - Those in NSW are being urged to stay up to date with public transport services which may be affected by the fires.
1:29pm - ABC reporter Julia Holman on Wednesday morning said air quality in the NSW town of Taree was still "really poor" from all the smoke.
"The local pharmacist told me they ran out of puffers yesterday [Tuesday]," she wrote on Twitter. "They won't be able to restock today because the Pacific Highway is still blocked."
1:13pm - The Australian Blood Service is urgently calling for more donors after raging bushfires forced Red Cross to close many of its donation centres in NSW.
"We do know that we collect around 15 percent of blood supplies for New South Wales in the areas where we have had to close our centres," Blood Service spokeswoman Helen Walsh told 9 News.
"Given the unpredictability of the fires, the reality is we're unlikely to immediately know the full impact on donations until later in the weeks," Walsh said on Wednesday.
1:06pm: Flames came "frighteningly close" to houses in the NSW suburb of South Turramurra on Tuesday, 7 News reported.
A clean up is underway on Wednesday.
"Pink fire retardant was dropped from the air and saved dozens of homes from the flames," 7 News reports.
12:58pm - A plume of smoke from the Australian bush fires is expected to make landfall across the North Island of New Zealand on Wednesday.
The plume is expected to appear in the western areas of the North Island on Wednesday evening, including Taranaki, Waikato, Northland and Auckland.
NIWA meteorologist Ben Noll told Newshub those areas of the country should be on "sunset watch".
12:23pm - Despite cooler conditions on Wednesday, the NSW Bureau of Meteorology says fire danger ratings remain high in the state's northeast.
"It at risk areas stay alert and prepared."
11:36am - Australian broadcaster 9 News says over 2000 firefighters battled the blazes overnight Tuesday.
11:32am - Sydney is expected to reach 23C on Wednesday, compared to Tuesday's scorching temperatures in the mid-30s.
11:10am - Weather warnings are in place for NSW's New England District due to severe fire danger. There's also a risk of "very high" fire danger in the Northern Slopes region.
11:08am - The Rural Fire Service says at least 50 homes were damaged or destroyed on Tuesday, confirming there was no loss of human life.
11:04am - Singer Ellie Goulding has sent a message of support to those effected by the fire.
10:42am - Koalas have been arriving at wildlife hospitals with soot all through their coats and serious burns, many of which haven't survived.
Northern NSW is home to a significant population of koalas, 7 News reported.
10:33am - A GoFundMe page to generate funds for vet medical supplies has raised more than NZ$4300.
In the space of two weeks, it's estimated more than half a koala colony was been wiped out by the fires.
10:29am - Australia Prime Minister Scott Morrison said late Tuesday (local time) "we are not out of the woods yet".
He thanked first responders for their "courageous" efforts.
10:19am - The Rural Fire Service says during Tuesday's dangerous fire weather conditions, 19 fires reached emergency levels.
As of Wednesday morning, two fires are burning at emergency levels.
10:12am - Sharon Chamberlain, a resident in the NSW town of Tinonee, told AAP it was "one of the hardest things" not knowing if her house was going to withstand the fires.
"How much more are we expected to take?"
10:01am - NSW Premier Gladys Berejiklian has been briefed on the current fire situation.
9:46am - Rural Fire Service Commissioner Shane Fitzsimmons says there's still an "enormous" challenge ahead.
"All these fires are still subject to the influence of this strong southerly change," he said, AAP reported.
8:50am - The fire service says as of 5am (local time) there were 73 fires burning across NSW with 37 yet to be contained.
Two fires are burning at emergency levels.
"Residents near active fires need to be aware of the potential for fire activity to increase under stronger winds," the Rural Fire Service says.
8:13am - The NSW Bureau of Meteorology says conditions have eased significantly across most of the state overnight but some properties were still lost.
8:02am - Firefighters are preparing for another big battle on Wednesday as a change in winds brings with it a new threat.
Millions of residents face another day of dangerous fire conditions.
Newshub's Australia correspondent Conor Whitten says the southerly wind change has caused a headache for firefighters.
7:45am - A neigbour of Russell Crowe is furious, claiming firefighters bypassed her friend's home to save the NSW-based Kiwi actor's property.
"I'm angry because our friend's house is there burning," neighbour Debbie Waldon told 7 News. "What about normal everyday people?"
7:26am - Speaking to The AM Show from NSW on Wednesday morning, Newshub's Australia correspondent Conor Whitten said a fire in the town of Hillville had been one of the most destructive.
"That has roared up again overnight, and that remains of great concern."
7:24am - Newshub's Australia correspondent Conor Whitten says four fires are now burning at emergency levels.
"A southerly change has swept through which has brought the temperature right down today [Wednesday]," he told The AM Show.
7:13am - Nine of the fires are still burning at emergency levels, ITV reported.
"Fires have already consumed more than a million hectares of land; three times more than the whole of last year," says ITV's Martha Fairlie.
7:03am - NSW-based Kiwi actor Russell Crowe says the fire reached his house on Tuesday.
"I'm not in Australia," he said in a Twitter post on Wednesday morning (NZ time). "My family are safe, billeted with friends.
"My heart goes out to everyone in the valley."
6:49am - Two firefighters were taken to hospital on Tuesday after suffering smoke innhalation while battling fires in NSW's Hunter Region, 7 News reported.
6:46am - The NSW Rural Fire Service says about 12 homes were lost in Tuesday's fires.
6:42am - Local meteorologists reported that a southerly change reached Sydney late Tuesday (local time), with a 69kmh wind gust at Sydney Airport.
6:30am - Australian authorities are warning they have a long way to go to contain the "enormous" bushfires raging across NSW
More than 70 fires are burning, with about half still uncontained.
6:00am - A fire that threatened to destroy dozens of multi-million dollar homes in a Sydney suburb may have been deliberately lit.
Australian broadcaster 7 News reported that the fire in Turramurra, in Sydney's upper north shore, was being investigated by police.
"Police were quickly on the scene, with fears it could have been the work of an arsonist," 7 News' Mark Riley reported.
5:48am - Earlier on Wednesday morning, the NSW Rural Fire Servive (RFS) said there had been an increase of fire due to a south-east wind change near the towns of Hillville, Nabiac, Failford and surrounding areas.
Residents were urged to seek shelter.
5:42am - New Zealand's upper North Island could see an extra vivid sunset on Wednesday night as a plume of dust carries over from Australia.
NIWA meteorologist Ben Noll says the dust also coated cars during the weekend in Wanaka.
5:40am - The Fire service says while conditions eased slightly on Tuesday night, a total fire ban remains in place as crews work to contain dozens of out of control blazes.
There will be no help from above either, with no forecast rainfall on the horizon.
Schools on the north coast will remain closed on Wednesday.