One home has been destroyed by a fast-moving and out-of-control bushfire near Canberra, on a day when temperatures soared across the state.
The blaze, referred to as the Currandooley fire, threatened homes at Boro and Mount Fairy, near Tarago, on Tuesday.
It burned through more than 2450 hectares of land since it broke out on Tuesday morning, causing an emergency warning to be issued for residents in the area.
The Rural Fire Service said it will inspect the fireground on Wednesday morning to confirm reports one home was lost in the blaze.
RFS incident controller Tim Carroll told The Goulburn Post that a weatherboard home on Hazeldell Road in Mount Fairy was lost as homeowners fought to protect it.
He said the homeowners, assisted by the RFS, did manage to save two sheds and were not injured by the blaze.
At least six sheep had to be put down by a vet after they were burned in the fire, Mr Carroll said.
Just before 6.30pm, residents were advised to "shelter in place" as the fire moved east, threatening properties on Duralla Place and Kalbilli Close in Mount Fairy.
Two waterbombing planes and 11 other aircraft helped firefighters tackle the blaze, which was downgraded to Watch and Act around an hour later.
Late-night rain helped further reduce the risk from the fire, which was downgraded to "Advice", however it was not completely extinguished.
As the fire burned, temperatures in Sydney hit 35.2 degrees just before 5pm, four degrees higher than predicted. There is no relief in sight until Wednesday afternoon.
Overnight, temperatures in Sydney were expected to remain above 25 degrees.
The Rural Fire Service has issued a total fire ban for Wednesday for Greater Sydney, as well as large parts of southern and central NSW.
The Bureau of Meteorology said temperatures would peak on Wednesday morning, before they eased in the afternoon.
"Relief is on the way, but brace yourselves for a horrible night on Tuesday," senior forecaster Neale Fraser said.
"We're still in the middle of the heatwave unfortunately, especially in western Sydney. There's a lot of hot air blowing over the top with the westerly.
"Wednesday will be another hot day until the cool change."
Sydney usually has just two days each summer when temperatures exceed 35 degrees. However, Tuesday equalled the previous record run of six days, which was set in the summer of 1990-1991. The forecast temperatures on Wednesday could see this record broken.
Another fire flared up on Tuesday afternoon in Gowan, near Bathurst. Sixty firefighters are fighting the 217-hectare blaze that is out of control, but not affecting property.
The cool change sweeping NSW on Wednesday was expected to bring easier firefighting conditions.
Light showers are predicted from Wednesday to Sunday throughout Sydney, with the potential for a thunderstorm on Wednesday afternoon.
Temperatures are set to hit 35 degrees by 11am in the city before dropping off about midday, while the west is forecast to reach 42 before the cool change hits later in the afternoon.
Sydney city's hottest night was recorded at 27.6 degrees on February 6, 2011. The second-warmest night was 27.1 degrees, on December 14 last year.
Penrith cracked a January record on Friday last week, dropping to a minimum of 25.5 degrees.