The delineation of natural areas in New Zealand: Climatic districts in New Zealand

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There is no generally accepted division of New Zealand into climatic districts. The whole country lies within the belt of prevailing westerly winds and the climate as a whole is usually described as moist, temperate. This is in agreement with the well-known system of classifying climates due to Koppen, according to which the whole of New Zealand, with a few minor exceptions, has the designation Cfb, that is, a warm, temperate, rainy climate without any marked dry season. Koppen's system is, however, not sensitive enough to distinguish climatic districts within New Zealand.
In 1931 Kidson published a map containing a subdivision of the country, using as an index the annual variation of rainfall. This map was modified in 1932 (see list of references) and again in 1937, when it was published as a map of climatic districts. Such an index, however, does not appear to be a satisfactory basis for representing the climate as a whole.