Temperatures are set to soar in parts of the country today, with firefighters and surf lifesavers urging people to take care during a burgeoning heatwave.
Sydney is set to reach 32 degrees today, rising even further to 34 degrees in Penrith.
The Rural Fire Service had to halt its hazard reduction burns around Sydney yesterday due to the heat and that is expected to extend through today.
The fire danger rating has risen to "high", which mean people in the Sydney region need to be ready to watch and act, and have their bushfire action plan ready.
And with a hot weekend building, Surf Life Saving NSW has warned everybody who plans to hit the water to stick to patrolled beaches and swim between the flags.
In Queensland, it's day one of the September school holidays, people are also urged to heed the flags and swim where it's safe.
Brisbane today is set for a top of 26 degrees, according to the Bureau of Meteorology.
The message from lifesavers along the 8000km of patrolled Queensland beaches is a simple one – they want to underline the importance of swimming between the flags.
Last season, 14 people drowned at Queensland beaches, and all of them were swimming outside patrolled areas.
Of the 3200 people who needed rescuing, 85 per cent were also outside the flags.
Queensland beaches are patrolled between 8am-5pm.
Temperatures will vary around the country's other capitals, with a 25 degree top forecast for Melbourne today.
Inland regions, particularly in the south and south-east, will see temperatures in the low to mid-30s, the BoM has forecast.
High temperatures will shift eastward on Sunday, with inland NSW likely to see peak temperatures in the high 30s.
The BoM's Miriam Bradbury said on X, formerly Twitter, while these temperatures weren't unusual for September, they were normally seen at the end of the month, and not for such a sustained period.
"It is uncommon to see a very, very warm period happening like this in the middle of September," she said.