Travelling in May & June

Hi All

I was planning to travel to visit my baby brother in Melbourne in Nov/Dec of last year but due to work committments had to cancel
Now I'm thinking of going in May and June but not sure if this is the best time? My plan was to travel via Hong Kong (3/4 nights), Thailand or Vietnam (1 week), then down to Australia (4 weeks). I had hoped to fly into Sydney, do Fraser Island and the Whitsundays, across to Alice Springs and then down to Melbourne. I know it will be cold in Melbourne then but what about the other areas I mention.
Also, will Asia kill me with humidity?

Thanks!

Well, you're right, it's not the best time for Melbourne (June is full on Winter!) however it's not that cold compared to European winter...and Queensland and the Centre are gorgeous in winter (not crowded, not hot but very pleasant - June actually a great time to go to Uluru to avoid the desert heat, especially if you want to do some hiking - highly recommended, especially at spectacular Kata Tjuta - less than an hours drive from Uluru/Ayers Rock). So as long as you are not looking for heat and long days and warm swims in the ocean, it's not a bad time at all! (I'm not sure about Asia!)