Ok.
Weather.
In Adelaide, which is in the south, we have what is known as a "meditteranean climate". I cannot spell it though.
So basically we have hot, dry summers with very little rain, but cooler wet winters. In the summer it's normally around 28 - 38, but we also do get days above 40 when it is very hot. It's a dry heat though, not humid at all. Plus all houses have air con. In the winter it never really goes below about 4-5, but it feels cold and you need heating. It's quite nice actually.
In Sydney it's different. There you have hot, wet summers and cool dry winters. You get torrential rain storms and it is much more humid. Winters are beautiful, crisp clear blue sky days for weeks on end. Fantastic. Weather in summer can be wonderful, can be very rainy.
Then in the north (Darwin, North Queensland) it is tropical - so dry, warm winters (lovely), very hot summers with a rainy season in Jan - about Feb/mar. You also get cyclones, big storms and flooding. It is beautiful between April and December though.
Brisbane (I think) gets the tail end of this. Storms, but not cyclones, rain but not flooding every year like in the north.
Working Hours
Sydney I would say I worked less hours than in London, Adelaide even less. Sydney is a work hard city though, similar to any other major city. I had a short commute but many don't as public transport is poor (although cheap) and pretty slow, especially compared to London.
Of course I have missed out Melbourne (but only because you haven't mentioned it).