New South Wales officials have said 600 firefighters remain on standby waiting to tackle any fires that may arise as temperatures across the state are forecast to reach up to 43 degrees today.
Authorities have warned that the intense heat, paired with strong winds are the recipe for extreme fire danger with total fire bans put in place across Greater Sydney to minimise fire risk.
The Saturday fire ban comes after NSW fire danger rated five districts as extreme risks, including in the Sydney area.
NSW Rural Fire Service Commissioner Trent Curtin said that 600 firefighters are ready to be deployed across the state and "are prepared to respond to fires throughout the day".
The NSW Rural Fire Service is dealing with 44 fires, four of them uncontained.
That includes a grass fire at Range Road, Mummel, Goulburn at watch and act level.
Curtin said that communities need to remain alert to conditions across the state today and minimise travel where they can.
Temperatures hit 27 degrees in some parts of the city as early as 5.30am.
Sydney Airport peaked at around 42 degrees, with Penrith similar.
But the hottest was 43 degrees at Sydney Olympic Park in, Homebush, one degree short of an all time record.
NSW Premier Chris Minns has alerted people to stay vigilant as Sydney's heatwave comes to a head today.