Wollongong has come within a whisker of its September heat record - but is due to smash that if forecast temperatures eventuate later in the week.
The weather station at Bellambi hit 32.7 degrees at 2pm on Saturday, September 16 - just 0.3 degrees shy of the September 28, 2008 record.
It's still more than 11 degrees hotter than the average September day of 20.1 degrees.
The week ahead is set to bring a heatwave to the Illawarra, with Wollongong tipped to reach 35 degrees on Monday and Wednesday, 34 degrees on Tuesday, and 31 degrees on Sunday.
Similar temperatures are expected in Albion Park, with 30 degrees on Sunday, 35 on Monday, and 34 on Tuesday and Wednesday.
Kiama can expect a top of 30 degrees on Sunday, and 34 degrees the subsequent three days.
The forecast has prompted a warning from health authorities, who urge people to take precautions against heat-related illness.
NSW Health executive director of health protection, Dr Jeremy McAnulty, said people should avoid physical activity during the day and stay well hydrated by drinking plenty of water.
"It's best to try and avoid the heat of the day by staying indoors and keeping curtains and blinds shut early. If you don't have air conditioning, using a fan, wetting your skin with a sponge, spray or water-soaked towel can help to keep you cool," Dr McAnulty said.
"If it's hard to keep yourself cool at home, you should also consider spending the day at cooler places, like the shopping centre or an air-conditioned community venue.
"People over 65, people with chronic medical conditions and babies and young children are particularly sensitive to the heat. Stay in regular contact with elderly neighbours, friends and relatives who may need help."
On Saturday, Albion Park reached 32.9 degrees, a way off the record 34.4 degrees experienced on September 23, 2017.
The average maximum temperature for the month is 21.3 degrees.
The mercury also peaked above 32 degrees at Kiama, which hit 32.2 degrees at 2.30pm.
It has a record temperature of 33.4 degrees (hit on September 30, 2014) but a September average of 20.1 degrees.
The Bureau of Meteorology's spring climate outlook advised of a hotter-than-average season for the region.
For those seeking relief from the heat, the only patrolled beach in the Illawarra at the moment is North Wollongong Beach.
The patrol season begins with the school holidays on Saturday, September 23 and many pools and beaches remain closed until then, or later.
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