While searching out some information on Northland, NZ, today, I found that the idea of what constitutes a 'city' in New Zealand is very loose. Some places seem to be self-proclamed cities, and others were cities, but became something else when there was a reformation of the districts.
However, New Zealanders confusion about what constitutes a city is nothing compared to what some overseas sites think are cities in the country.
Wikimedia Commons has a page named Category: Cities in New Zealand.
In this list we find the villages of Akaroa, Bluff and Port Chalmers, and the towns of Lyttelton and Mosgiel. The latter two are at the very least outer suburbs of bigger cities (Christchurch and Dunedin) and the former three have similar status.
On another site, Big Daddy Data, the Bay of Plenty is listed as a city. Considering that the Bay of Plenty is a conglomeration of little settlements, mostly independent of each other, this is peculiar.
A site called C2: Cities of New Zealand includes Queenstown as a city, but it appears to be written by a couple of bods with limited understanding of the area. Queenstown may be on the way to being a city, but I'm not sure that it's quite got there yet. The site also claims that Dunedin has 'Lousy weather much of the time.' Obviously a limited understanding. It also manages to include Blenheim, Greymouth and Hokitika as cities. Rather suspect information here.
A last example is a site called Mongabay.com, which helpfully gives the estimates of various cities throughout the country as at 2005. These have obviously been worked out by some computer somewhere that doesn't know how to round off figures. It also hasn't been programmed to eliminate places that are under a certain population figure. This one includes the cities of Dannevirke, Gore, Huntly, Kaitaia, Matamata, Waiheke Island (?) and more. Enough said. Don't believe everything you find on the Net.