The city is today sweltering under severe heatwave conditions while a total fire ban is in place across the metropolitan area.
Sydneysiders have been warned over the risks of what experts dubbed a "silent killer" as a heatwave grips the city.
The city is today sweltering under severe heatwave conditions while a total fire ban is in place across the metropolitan area.
The NSW capital woke up to an abnormally hot March morning, with temperatures already topping 28 degrees before sunrise.
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Parts of the west nudged 36 degrees by lunch time, with the city around 34 degrees.
NSW Ambulance associate director for emergency management Steve Vaughan said he anticipated Triple-Zero calls to spike amid the extreme heat.
He said paramedics were braced to get around 3500 calls for help.
"We generally see an increase of Triple-Zero calls in hotter weather," Vaughan said.
"It's unseasonable, being in March, seeing summer temperatures . It's a timely reminder heatwave season is not over yet."
Vaughan described heatwaves as a "silent killer" and advised people to look out for the elderly and children.
"Heatwave is the biggest natural disaster killer, it kills more people than fire or flood," he said.
He also warned against ever leaving children in cars.
"Do not ever leave them in the car, temperatures will spike very very quickly," Vaughan added.
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Suburbs in western Sydney are facing the hottest temperatures, including Penrith and Campbelltown, while Sydney city are sweating under the mid to high 30s too.
Just after 1pm it was 34 degrees at Richmond in the north west.
Badgery's Creek it the west was 34 degrees and Canterbury was 35 degrees.
Horsely Park was nudging 36 degrees.
The Bureau of Meteorology issued a heatwave warning for all of metropolitan Sydney, with a low-intensity heatwave across NSW extending as far as Broken Hill and Albury.
Kiama on the south-coast was NSW's hottest area earlier this morning, with temperatures already at 32 degrees just after 8am.
Today's heatwave conditions are expected to linger until midnight and a cool change is expected for tomorrow.
"Today is the hottest day, and then it is the end – well, that is the hope," said senior meteorologist Magda Gallos-Lorenc.
The heat has prompted a total fire ban across greater Sydney, the central ranges, southern slopes and southern ranges regions.
Dry and hot wind gusts today could exacerbate any fires and the Rural Fire Service has advised any residents in high-risk areas to activate their survival plan.
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NSW Ambulance has also warned Sydneysiders to avoid going outside during the warmest times of the day.
"Stay hydrated and avoid outdoor activities during the hottest parts of the day," NSW Ambulance said.
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