It still gets bitterly cold for most Aussies during winter
OK... so you have no feeling in your legs or your fashion sense is more important that common sense (because I can't think of any other way to describe someone who lives in a climate that goes from so hot to so cold without changing pants).... I can get behind that. I went Uni with a guy who wore shorts year round too and we used to rib him to death... he joined in by the way, we didn't just insult him out of hand.
By the way does it ever get up around 46C or 47C where you live?
Truthfully, our summers rarely hit over 110F and even then never for much longer than a week to 10 days. But we struggle with it as, in general, it's not a climate we've much experience with and therefore little tolerance for. I used to spend a month or so from late June to late July with a friend who lived in Arizona each year. Because it was the dead of Summer the average temp. was about 108F on a daily basis with regular forays into the 120s "just for fun".... and then of course the monsoons would hit!
But honestly, my memories of life in the desert are still some of my most beautiful. I know that many people find it desolate and the heat unbearable but I always found it full of life, stunning in it's vistas and Arizona itself a magical state with a number of different biomes occupying it that made for a place that was always changing and always worth watching. So I learned to acclimate to the heat, look at cacti with the awe they deserve if you know their history and what it takes for them to survive and I learned to survive blast furnace heat that in some parts of the state, could suck the air out of your lungs when you got out of the car.
Although in the end, I would still prefer to retire to New Mexico (Albuquerque and/or Santa Fe) which has a climate a bit more moderate, stunning mountains, desert vistas and the beautiful old city of Santa Fe which is a tiny miracle of land with the remains of old settlements, a stunning old church with a staircase carved out of one solid piece of wood and made out of local clay.... and an artistic community to rival any I've seen. They even have week-end "swap meets" (which hardly does the grounds and products justice) where you can go to find virtually anything you can imagine. From hundred year old Navaho jewelry to Haute Couture knock-off purses, to all kinds of work by local artists to Kewpie Dolls.... it's magical, miraculous and in a way.... a kind of "Disneyland" all on it's own.
So while I don't have the experience of Australia, I'll defend your right to wear shorts to your death if need be (although I still think it just a bit "touched") and love the idea of it's countryside and climate as much as is possible for a person who has never been there.
And dancing bunnies for the desert (where you can still find them in Vegas!)
Well damn CS.... I can't find you a cool guy with a ball cap.... that just ain't right! Have a crown... 
you rule my world!
