That I have not been truly hot for the last 10 years since I left Australia and well it's true. Even my part of Spain is hottest at a quite pleasant 96F so I do oddly miss those 100+ days.

Having said that these extended heatwaves back home seem to be intensifying year after year. Sure 40 degC and over happened a few times a year but not for weeks on end and multiple times a summer at that.
Sad to say but we are really the front line of climate change, expect more of this.

12 Celsius does equal 53 degrees if you're talking about air temperatures, as in "The low tonight in Sydney will be 12 degrees." However, this should be 21.6 (or 22 F) higher than normal - 12 X 1.8 = 21.6

https://www.metric-conversions.org/temperature/celsius-to-fahrenheit.htm

And, btw, 22 F above average is really an enormous variation.

Source: The Guardian

Australia extreme heatwave: records broken for highest minimum temperatures

Severe weather conditions forecast to bring maximum temperatures 8C to 16C above average, as three towns record overnight minimums of 33C

Lisa Cox
Tue 15 Jan 2019 01.52 GMT Last modified on Tue 15 Jan 2019 04.18 GMT

All-time highest minimum temperatures have been broken in three places as a heatwave sets in across much of Australia, threatening more record hot days.

Meekatharra in Western Australia and Fowlers Gap and White Cliffs in New South Wales all registered an overnight minimum of 33C on Monday.

Severe to extreme heatwave conditions extending from the interior of WA across South Australia, Tasmania, Victoria, the ACT and NSW will bring maximum temperatures of 8C to 12C above average, and in some places up to 16C above average before the end of the week.

From Tuesday through to Friday, parts of South Australia, Victoria and NSW may break January heat records, with daytime maximums extending up to the mid-40s.

-snip-

Read more: https://www.theguardian.com/australia-news/2019/jan/15/australia-extreme-heatwave-records-broken-amid-all-time-highest-minimum-temperatures