I have been looking at the same thing.
Here are some comments I found "I would avoid the December - April period for the East Coast of Australia, north of
Brisbane it is the wet season, sometimes it can rain for a week or more at a time, and
roads/railways are often cut by flooding. It is very humid and hot during this time, also
with Darwin during that period. It is just plain hot at Alice Springs/Uluru then. Anywhere
else you've mentioned in Australia/NZ OK any time of year, whilst you get the occasion
snowfall in the high country in July-September in New Zeland (particularly south island)
and Tasmania - if you want to get detailed climate info try www.bom.gov.au"