Climate of New Zealand

New Zealand's climate is extremely complex and varies from warm subtropics to colder alpine mountainous regions. Average mean temperatures on the island vary from about 10°C in the south to 16°C in the north of New Zealand. Like most areas that are surrounded by water, the temperature changes from winter to summer is smaller then those that are landlocked. 

https://www.niwa.co.nz/sites/niwa.co.nz/files/styles/large/public/sites/default/files/images/climate_-_nz_temperature_1971-2000.jpg?itok=HR6i5BPT

New Zealand is usually hit by only one storm of tropical origin each year. Between December and April several tropical storms head toward New Zealand but many of them lose their hurricane characteristics as the get closer to the islands. New Zealand uses a scale for the different power of these tropical storms.

Classification of south-west Pacific tropical cyclones

Intensity Class	Description	Speed range (knots)	Central pressure (hPa)
1	Tropical depression	<34	>995
2	Gale	34-47	995-986
3	Storm	48-63	985-975
4	Hurricane	>63	<975

https://www.niwa.co.nz/publications/wa/vol10-no1-march-2002/how-often-is-new-zealand-hit-by-tropical-cyclones

Another deadly weather phenomenon that occurs on the islands of New Zealand is tornadoes. New Zealand reports about 20 tornadoes a year! Not even significant to the how much the United States reports per year, but it goes to show how much the weather varies on these two islands. 

http://tvnz.co.nz/national-news/one-man-dead-tornado-wreaks-havoc-in-auckland-4152830