Hi Kim,
As Gaye said, anything can happen. We've certainly been having plenty of snow and wild weather this August, and blue skies can turn to freezing conditions any time of year. But you could have gorgeous weather too.
As you haven't had much experience, and are from sunny Qld, I'd suggest erring on the side of caution. If there's any ice or snow around, I'd give the summit a miss. There's a lot of scrambling up and over rocks to get there, which can be pretty treacherous if wet or icy. You may have heard a tourist slipped to his death from near the summit a few years back.
But there are still plenty of beautiful walks to do, as Gaye said. It's less likely to be icy lower down. You could do a longer walk up (one of various ways) to Kitchen Hut, across the Face Track, visit Twisted Lakes and go back down over Hansen's Peak. It's steep but there's a chain to hang onto if you need it. Or do that walk the other way, or up or down via Lake Wilks. If you do a higher circuit like that, and have heaps of time and energy, you could even add a down-and-back visit to Artist's Pool, which is on the way to Lake Rodway.
Using the shuttle bus, you could start your walk at Ronny Creek and finish at Dove Lake if you like. It's very pretty up via Crater Falls, and that would give you a fair bit of variety with the higher bits.
Have fun
