weather and timing
The weather across most of New Zealand is pretty moderate due to the fact that it is a bunch islands surrounded by an immense amount of ocean. Aotearoa, the Maori name for New Zealand, means “land of the long white cloud.” That should give a clue that it does have a tendency to rain here, so be prepared for that.
It is also important to remember that there is a huge range of climates that go from a sub-tropical like San Diego (Northland) to Vancouver Island, Canada (Stewart Island). So a question like “what’s the weather like?” is pretty hard to answer, but I will try.
A great resource to study up on is on the NIWA website
Temperatures:

The map on the left shows the median annual temperatures across New Zealand. To the far north, it can get a bit hot and humid in the summer and very pleasant in the winter. In the South, it can be pleasantly cool in the summer and freezing-ass in the winter.
A typical summer day in Auckland will be 24o C (75o F). It will be similar for Christchurch on the South Island. The big difference is that Auckland northward gets quite humid in the summer.
Dunedin averages 17o C in the summer. From Dunedin south, it gets much cooler. The inland valleys in Otago and Canterbury can get up into the 30’s on a hot summer day.
Obviously, the high mountains can be quite a bit cooler if you are off doing a tramp somewhere.
Rainfall

(click to expand)
The North Island is very green and lush due to the fairly high and consistent amount of rain, even in the summer. North of Auckland is quite rainy. Taupo area is much drier. The Kapati coast (east coast of North Island) is always wet and windy. Wellington is famous for its wet, windy weather.
The South Island is the tale of two worlds. The east coast is quite dry and looks a lot like Bozeman Montana in places. The West Coast is the Olympic Peninsula where you are almost guaranteed to get soaked to a squishy. Fiordland is some of the highest rainfalls in the world, in places topping 9 meters a year.
The fall is probably the most stable weather in New Zealand with the least amount of rain. November and December can be a bit unsettled but warm.
If you like to ski, then July and August are probably your best bet for finding some snow. Just remember, this will not be Colorado or Utah with big fluffy powder; think East Coast ice.
When’s the best Time?
February, March and April are, in our humble opinion, the best time to be in New Zealand. The weather is still warm and far more stable and predictable than in the Spring and early Summer. Winter is a bit dreary if you are on vacation, so I really would advocate for that.


Let me know what you think!