Sydney is experiencing its hottest day on record, with temperatures reaching nearly 115 F (46 C).
A temperature of 114.4 F (45.8 C) was recorded at Observatory Hill in the Australian city at 14:55 local time.
Some areas in the wider Sydney region were even hotter, with the town of Penrith, to the west, registering a temperature of 115.7 F (46.5 C).
Firefighters are still battling dozens of wildfires sparked by the intense heat in New South Wales and Victoria.
The small town of Licola in eastern Victoria is reported to have been cut off by a 44,500-hectare fire, as its sole access road is blocked.
Officials said dozens of people had been evacuated but 10 locals were still there.
Rob Gilder, a sheep farmer, said he and two employees had found themselves trapped on their farm and were “in grave danger”.
He told the Herald Sun they were taking steps to protect their house and farm equipment, but that he was concerned for his livestock, and that the situation could worsen.
“I am very worried. But I am hopeful that one of those helicopters will come and get us but I think the smoke might beat them.”
Australia faces wildfires each year as temperatures climb. In February 2009, on what has come to be known as Black Saturday, 173 people were killed in fires in the state of Victoria.
On Friday, Prime Minister Julia Gillard attended a memorial service for fires in 2003 in the capital, Canberra, which killed four people and destroyed thousands of homes.
She reminded Australians to “take the appropriate precautions to stay safe and monitor information from local emergency services as they work to protect lives and property”, the AFP news agency reports.
The previous recorded high in Sydney was in January 1939, when the thermometer topped 113.5 F (45.3 C) at Observatory Hill.
The Bureau of Meteorology said in a statement that Friday’s record-setting temperatures “were not limited to Sydney, with records being set along the coast from Bega (44.6 °C) to Williamtown (44.8 °C)”.
“The highest temperature recorded in the Greater Sydney Area was 46.5 °C at Penrith, where observations started in 1995.”
Officials in Sydney have warned people to be ready for the heat, take care, avoid strenuous activity and stay out of the sun.
The heat has damaged wiring to urban railway lines, bringing delays to much of the network – CityRail have warned passengers to carry water with them.
The emergency services has received dozens of calls from people seeking help for heat-related health issues, including dizziness, fainting and vomiting, ABC News reports.
Chief Superintendent Ian Johns said elderly and ill people tended to suffer the most, but warned that “people underestimate the heat and overestimate their ability and that would be particularly so for younger, fitter Australians”.
The heatwave across Australia in recent weeks has been so intense that the Bureau of Meteorology has had to add a new shade to its color-coded temperature chart, so the scale now reaches above 122 F (50 C).
However, meteorologists have forecast a dramatic change in weather overnight in Sydney, with thunder storms expected to bring a rapid drop in temperatures.