Mean annual temperature data layer used in the creation of Land Environments of New Zealand (LENZ) classification. The classification layers have been made publicly available by the Ministry for the Environment (see koordinates.com/#/layers/?q=LENZ for to access these layers).
Mean annual temperature is recorded in °C. The climate station data used in the development of this climate surface were derived from summaries of climate observations published by the New Zealand Meteorological Service, using data collected over the period from 1950-1980. The resulting data layer was created by coupling a 100 m DEM with a thin-plate spline surface fitted to an irregular network of 300 meteorological stations. The resulting 100 metre layer was then interpolated to 25 metres using bilinear interpolation. Following conventions used in the calculation of climate summary statistics, the values used to fit the surface consisted of the mean of the 12 monthly averages for daily average temperature.
This layer has been multiplied by a factor of 10 (i.e. converted into an integer grid) to save space and make the grids more responsive. A value of 136 is actually 13.6 °C.
Additional details such as the climate station locations used in the creation of the layer and error maps are defined in the attached LENZ Technical Guide.