2 years ago in Australia, was going from Darwin to Perth and for about 2 weeks between Darwin and Broome we had 40+ every day. I think the highest I've seen was 45. Worst part was that we were camping along the way so we had to sleep in this heat, during the day it was really bad at all but it never really cooled down to lower than 27 at night. On top of that, the ground seemed to have gotten so hot during the day that it radiated heat through the night, I could feel the heat coming up as I was going to sleep.
The major cities in Australia get that too though, in Melbourne I've experienced 40+ a couple of times but it never lasted more than a few hours.