I'll buck the trend and call it at least a 5 or 6, based on how often I've had the wee beastie out to play (most recently last night). And that's not counting the inevitable clear evenings when I'm out socialising! Though there's definitely been more high clouds this spring than last, there's always a reasonable number of decent nights if you're ready for them. It's all too easy for people to remember the bad nights and forget the good ones. Melbourne's a far superior climate for astronomy than many other parts of the world, and I'm glad it's not a desert climate!
The weather's been fun too - heat/humidity records last week, thunderstorms last week and tonight, spectacular cool change earlier today after another 37C. Certainly beats an Edinburgh summer!