The mercury will hit 36C in Sydney on Friday, breaking the city’s October average by 14 degrees.
Sydneysiders are being urged to drink plenty of water and not leave children, the elderly or pets in cars with the mercury forecast to hit 36C – 14 degrees above the city’s October average.
The Bureau of Meteorology NSW said 36C was also expected in Penrith in the city’s west on Friday, 10 degrees above the October average.
It will be the hottest day in Sydney since March 6.
BOM NSW forecaster Helen Kirkup said strong north-westerly winds would keep the cooling sea breeze away from the city and coastal areas until later in the day.
“Those north-westerly winds will continue all day and that will keep the temperatures up right across Sydney,” she told AAP.
“But Bondi has a top of 33 degrees, which means they should see a north-easterly later this afternoon.”
Emergency services said NSW visitors and residents should keep cool and take care of those at risk of heat-related illnesses.
“Motorists are reminded it is never okay to leave children, the elderly, or pets unattended in a car – even with the air conditioning running. Not only is this dangerous, it can be deadly,” NSW Police said in a statement.
Total fire bans are in place for the far south coast, Central Ranges, greater Hunter and in the state’s north west.
There is very high fire danger across much of NSW, including Sydney.
By Gus McCubbing