Promoting a small nation to the world which has such a variable climate, is no easy task.

holidays-in-newzealand.com have had a crack and have gone into some detail!

New Zealand weather tends to be variable because we are in the mid latitudes, it is very changeable, with a wind flow from west to east. The highs and lows of the weather system are carried along this flow, meaning the weather comes from the west. 
Air from tropical areas is usually wetter than from the polar region and generally these two air flows do not mix. The air in New Zealand has blown across wide expanses of sea picking up moisture as it goes. Being such a long narrow country the furtherest point from the sea is no more than 145 kilometers. This means frequent rain is part of the New Zealand weather pattern.

Our mountains, especially the Southern Alps, are high enough to precipitate rain, so the west coast of the South Island is the wettest area.

The sunniest places are Blenheim and Nelson at the top of the South Island, and Whakatane on the east coast of the North Island.

New Zealand weather is generally sunnier than many countries experience in winter, with relatively few thunderstorms. It depends where you are what frosts, if any, you are likely to encounter.

The average summer temperatures range from 20-30 degrees C. The average winter temperatures range from 10- 15 degrees C. Daily temperatures can vary by 10- 15 degrees throughout the country. So you need to be prepared for quite a variety of weather and temperatures any time of year, especially if you are travelling through both islands.  

Daylight Saving – You can expect daylight to last till about 9.00pm in summer. We have daylight saving in New Zealand which starts the last weekend of September when clocks are put forward an hour, and finishes the first weekend of April.

Summer – December to February. The longest day is 21st December and Labour weekend – the last weekend in October was always the start of summer activities,including swimming in the sea! However, this tends to be a bit later these day.Christmas is outside if we are lucky, but the hottest most settled weather is usually February running into March.Autumn -March – May often has lovely settled weather. New Zealand native trees are not deciduous so you do not get pronounced seasonal changes in the north, but Otago and Hawkes Bay where there are a lot of English trees, has beautiful autumn colours.

Spring –September – November will have great displays of blossoms, lambs and calves in the paddocks and beautiful flowers in the parks and gardens. Christchurch city is particularly lovely in spring.The weather is often settled and it is a nice time to travel.November can be windy.