Anne Droniou

New Zealand’s location in the Southern Hemisphere, or south of the equator, means that its seasons are opposite to those in the Northern Hemisphere. The warmest months of summer are January and February and the coldest months of winter are June and July. New Zealand is located in the Southern Temperate Zone, south of the tropics. It has a mild climate with four seasons.

Temperatures tend to be warmer in the north than in the south; the warmest area is in the extreme northern end of the North Island, and the coldest area is on the south-western slopes of the Southern Alps. In most of the country, however, there are only minimal climatic differences between north and south. Average low winter temperatures range from 2°C in Christchurch, on the South Island’s central east coast, to 8°C in Auckland, in the northwest of the North Island. Average high summer temperatures are 23°C in Auckland and 21°C in Christchurch.

New Zealand is located in the “Roaring Forties” wind belt, an area between latitudes 40° and 50° south where westerly winds sweep across the southern ocean.

Mean temperatures at sea level decrease steadily southwards from about 15°C in the far north to about 10°C in the south of the South Island. Temperatures also drop, by about 2°C per 300m, with altitude.

The extremes for New Zealand are 42°C. Which has been recorded in three places, in the Atwater Valley (Marlborough), Christchurch, and Rangiora (Canterbury); and -22°C at Ophir (Central Otago)? The annual range of mean temperature (the difference between the mean temperature of the warmest and coldest months) is small. In Northland and in western districts of both Islands it is about 8°C and for the remainder of the North Island and east coast districts of the South Island it is 9°10°C. Further inland the annual range exceeds 11°C in places, reaching a maximum of 14°C in Central Otago where there is an approach to a 'continental' type of climate.

The sunniest places are near Blenheim, the Nelson-Motueka area, and Whakatane, where the average duration of bright sunshine exceeds 2350 hours a year. The rest of the Bay of Plenty and Napier are only slightly less sunny. A large portion of the country has at least 2000 hours, and even Westland, despite its high rainfall, has 1800 hours. Southland and coastal Otago, where sunshine drops sharply to about 1700hours a year, lie on the northern fringe of a broad zone of increasing cloudiness.

Return to geography