A severe heatwave warning has been issued for the ACT, stretching out to Friday.
A sunny top of 33 is expected in Canberra on Wednesday, followed by a partly cloudy 31 on Thursday before showers are likely coming in on Friday.
The Bureau of Meteorology said severe heatwave conditions were developing across parts of the ACT during the week and were expected to peak on Saturday with a top of 36.
"Heatwave conditions expected to ease over the weekend with a cooler change," the bureau said, adding that Belconnen, Gungahlin and Woden Valley were the locations likely to be impacted.
The bureau defines a heatwave as when the maximum and minimum temperatures are unusually hot over three days compared with normal.
Saturday is expected to be windy, with temperatures dropping to 27 on Sunday.
The bureau has warned that severe heatwaves could be dangerous for many, especially older people, babies, children, pregnant and breastfeeding women and those with medical conditions.
lt has urged Australians to keep cool, including by turning on air conditioning and closing the blinds.
No total fire bans were declared but the NSW Rural Fire Service urged people in bushfire prone areas to have an action plan ready in the case of an emergency.
NSW Police reminded commuters to keep their cool on the roads, particularly if there were traffic delays.
"We know many people will want to head to the beach, a local swimming hole or swim in your backyard pool, please be careful," a NSW Police spokesperson said.
"Keep a watchful eye over children especially when they are near the water, all children need to be supervised."
Leading up to a scorching week, the ACT government has urged residents to stay safe around waterways.
The hot weather is expected to impact much of the country. Much of NSW and parts of Queensland, South Australia, West Australia, the Northern Territory and ACT are predicted to cop soaring temperatures until Friday.
NSW residents are in for a sweltering period with a severe heatwave warning issued from Wednesday which is expected to last for the next three days.
Residents in the northern tablelands, central west slopes and plains and lower and upper western districts are being warned by the Bureau of Meteorology about above average maximum temperatures, with some areas tipped to reach the high 30C degreesto low 40 degrees.
The Illawarra, Hunter and Riverina regions were also issued with a severe heatwave warning.
-With AAP
