New Zealand and Australia…Where to First?

Are you planning on any other parts of Australia apart from Tasmania?

We have been to Australia and New Zealand twice and there is a lot to see in those countries.
5 weeks is a lot, but you won't see all. You need at least two weeks to do both the north and south islands of NZ.
We only did the north island in 9 days.
We did a cruise the first time in Australia from Perth over the top of Australia ending in Sydney and did 6 days in Sydney.
The next trip we did Sydney again, as well as Melbourne and the Great Ocean Road and Phillip Island (to see the penguins come in.
Don't miss the GOR and Phillip.
We didn't spend enough time in Queensland to do justice to the Great Barrier Reef, try to see that well.
We did the Blue Mountains on a day trip from Sydney.
Also, in Sydney there are some wonderful museums there as well as the zoo. Do Bondi Beach, a harbor cruise and the bridge piles climb (its two thirds of the way up and WAY cheaper).
Also, we saw a great opera at the famous opera house.

Thanks for your thoughts. I spent 4 weeks this last March and April on the East Coast of Australia, including 4 nights in Hobart. I was traveling with a friend. We covered from south of Melbourne on the Great Ocean Road up to the Daintree Rain Forest. We spent time in Melbourne, Brisbane and Sidney as well as smaller towns. We snorkeled at the Great Barrier Reef twice, in two different locations. This year’s trip will be focused on New Zealand and I would like to see both islands since I don’t think that we would have the opportunity to return. We aren’t interested in a cruise. I think my husband would really like Tasmania and he is interested in seeing it. I don’t want this to be a trip to Australia, but a trip to NZ with a short side trip to Tasmania. If we have to cut something it will be that.

I don't know whether it would be better to go to Tasmania first or last. But whether you fly there from the US or New Zealand, there is a good chance you might need to transit through Sydney or Melbourne airport. Of these Melbourne would be the easier airport for transit. The international and domestic terminals there are all in one building which makes transit just an easy walk. In Sydney Airport, international and domestic terminals are different buildings on opposite sides of the airport so requires a bus trip.

I don’t think, weather-wise, it would make much difference, and the school holidays end in mid October in both NZ and Tasmania. I can’t really think of a reason why either option would be preferable after the other. I would most likely go with whatever was more convenient flight-wise.
Great choices, I’m sure you will enjoy both at that time of the year. We were on the South Island of NZ in November this year and the weather was great.

A week in Tasmania is the minimum needed to do a loop and even then, you will need to decide which things to cull from your "must see" list.
The later in your 5 weeks that you leave Tasmania, the warmer the weather will be, although in the scheme of things will be not that pronounced. Also the later on gives more daylight hours per day.

Having more time to think, and after seeing the replies, I see you are only interested in Tasmania in Australia.
To place Tasmania in the mix with the least fuss & airport time, I would fly non-stop LAX-AKL Spend 10 days South Island. Then AKL-HOB, 7 days Tassie. Hobart to Christchurch (via Melbourne) 14 days South Island. Then United & Air New Zealand do a one stop flight to SMF.
If using the above, start with home on the 20th Nov and work backwards with flights choosing days on best price & airline available.

IMHO prioritise NZ and perhaps finish with a chill 4 or 5 days in Tassie before you fly home.
5 weeks is not a heap of time to squeeze in the best of the North and South Islands. We did 3 week roadies on each island and we had to be very selective.
I would fly to Auckland (North Island) first and head north initially then back to Auckland and then head south. Are you thinking ferry between the two or flying from Auckland to South Island either Christchurch or Queenstown?
All are reasonable options. Simple enough to work a nice practical loop back to Auckland or just keep heading south.
Once on the South Island most people head to the Southern Alps and Fiordland. Pretty straightforward route options. We did a 3 week loop with a Fiordland extension starting and finishing in Christchurch. There is plenty more to see but time will be the problem. The South Island scenery is the more dramatic. Also it is a harsher winter so the later you do it possibly the better the weather.
Flights from Christchurch to Melbourne are regular. Christchurch is a very easy airport to navigate too. You know the drill with flights from Melbourne to Hobart. You would have all the hard travel done and you can just take it easy in not very bustling Tassie. Maybe chase up Ron the Tassie Devil for some shonky tour guiding.

Since you are in Northern California and likely Star Alliance people, some ticketing thoughts:

-Air New Zealand codeshares with United

-United flies nonstop SFO to Christchurch (South Island) and avoids the Auckland international/domestic connection song and dance

-Air New Zealand flies nonstop between Hobart and Auckland

If it works time wise I would fly via Auckland to start in Hobart, back to Auckland, finish to Christchurch for the nonstop home.

Thanks again everyone. I’m not quite ready to book my flights yet and want to have a general plan when I do. Toby is correct that I prefer United and Star Alliance Flights. Unless the prices make me reconsider we will fly from Sacramento to Auckland, likely by way of SFO or LAX. After the North Island we would fly to the South Island, then later to Hobart. Depending on if we can leave a little earlier than planned maybe we will go to Sydney for a few nights before flying home. I checked flights from San Francisco and they were considerably more than the flights from Sacramento. Strange but true, at least at that moment.

Pleb, I will most certainly try to meet up with Tassie Devil Ron in Tasmania. My friend and I spent a lovely afternoon with him last March.