The most extensive heatwave of the summer is building over inland Australia, setting up Sydney and much of the state for record-tilting heat over the coming weekend.
The extreme heat comes after Sydney mopped up for a second day following Tuesday's heavy rainfall. Damage from the event included a large sinkhole opening up in Point Piper, less than a kilometre from Prime Minister Malcolm Turnbull's house.
More National News Videos
Sinkhole opens up near PM's house
A near neighbour of Malcolm Turnbull in one of Sydney's most exclusive suburbs expresses her shock at the sinkhole which has opened up near the PM's house.
An area roughly the size of NSW will endure temperatures of 45 degrees or hotter on Saturday, elevating temperatures and fire risks across much of the nation's south east, the Bureau of Meteorology said.
For Sydney, wet weather on Tuesday and Wednesday will make way for steadily warmer conditions as the interior heat leaks eastwards.
![Even coastal areas are going to face scorching temperatures over the coming days.](/web/20170208075528im_/http://www.theage.com.au/content/dam/images/g/u/8/6/w/z/image.related.articleLeadwide.620x349.gu7sdq.png/1486535672658.jpg)
A top of 29 degrees is predicted for Sydney on Thursday before a trio of scorching days, with 36, 39, and 38 degrees forecast by the Bureau of Meteorology for Friday through to Sunday.
For places such as Penrith, Thursday's forecast top of 36 degrees will seem almost cool given what's expected after that. Friday to Sunday will see the mercury climb to 44-45 degrees.
"This could be the hottest three-day spell on record for the city," Graeme Brittain, a meteorologist with Weatherzone, said.
David Martin, a senior climatologist at the bureau, said it was rare for Sydney to record three days in a row of 35 degrees. The last time was in early January 1994.
![Arianne Elliots demonstrates how not to stay cool on a hot evening at Bronte Beach.](/web/20170208075528im_/http://www.theage.com.au/content/dam/images/g/u/8/6/a/0/image.related.articleLeadwide.620x349.gu7sdq.png/1486535672658.jpg)
The city has only had four such runs in its history, although it will be hard-pressed to beat the stretch of four days in January 1960, when each day topped 39 degrees and two of them were above 41 degrees.
Even if Sydney misses out, the scale and longevity of the abnormal heat is likely to break heat records either for February, or for any month.
![Big rains this week left a trail of destruction in Sydney, including in Point Piper, where a sinkhole opened up on Wednesday.](/web/20170208075528im_/http://www.theage.com.au/content/dam/images/g/u/7/y/s/t/image.related.articleLeadwide.620x349.gu7sdq.png/1486535672658.jpg)
Three NSW towns are also in the running to beat the current record of 50 days above 35 degrees: Walgett, Moree and Mungindi, Dr Martin said.
The largest area of scorching conditions during the current heatwave may come on Saturday (see bureau chart below).
![](http://web.archive.org./web/20170208075528im_/http://www.smh.com.au/content/dam/images/g/u/8/a/z/y/image.imgtype.articleLeadwide.620x0.png)
The widespread heat has brought at least low-intensity heatwave conditions to large parts of eastern Australia for several days.
The coming heat burst will include regions of severe or even extreme heatwave conditions for parts of eastern NSW, the bureau said (see Twitter animation below).
Severe #Heatwave conditions in #SA extending gradually to #VIC #NSW and #QLD . Take care & stay well hydrated https://t.co/ByG5YyVjFH pic.twitter.com/iKIJT4OTjM
— BOM Australia (@BOM_au) February 8, 2017
Sinkhole
The hot spell comes after several days of rain, some of it causing flash floods, in parts of Sydney.
Work crews continued to mop up on Wednesday, as well as deal with new problems such as a large sinkhole opening up in Point Piper near a vacant property.
Kristy Mirzikinian, who lives on Wentworth Street, said she could smell gas on Tuesday afternoon, and workmen came and were "banging around, breaking down the concrete" at the site.
She said she woke on Wednesday to discover the hole had opened up.
"I'm just in shock. I can't believe [there is] a hole right across the street from my house," she said.
The mansion next to the site is on the market with an asking price of $11.5 million. The "luxury family home with expansive water views" is listed as having six bedrooms, eight bathrooms, a six-car garage and two lap pools, as well as views across Rose Bay.
Fire threat
While the rain will have eased the bushfire threat near Sydney, much of the state got little of the rain.
The Rural Fire Service is predicting conditions will worsen in coming days, deputy commissioner Rob Rogers said in a tweet:
Have just been looking at the weather for the weekend, and we are going to be in for some more nasty fire weather. #nswfire
— Rob Rogers (@robrfs) February 8, 2017
Weatherzone's Mr Brittain said the coming heatwave could be the last intense event for Sydney for the summer, with conditions looking milder over the following week or two.
After the weekend, Sydney's temperatures should drop back to maximums of 23-26 degrees for the first three days of next week.
Most nights will remain well above average for February, the bureau said.
Weatherzone is owned by Fairfax Media, publisher of this website.
with Megan Levy