Northland rainfall maps are generated from a network of about 40 automatic rain gauges operated principally by Northland Regional Council but also including some operated by MetService and NIWA.
Produced and available on or about the first working day of the following month, the maps are based on how much rain has been recorded at the automatic rain gauge sites as a percentage of what would normally be expected (ie percentage of normal). The ‘percentage of normal’ contours are based on these points.
From November 2016 maps will report the percentage of median rainfall.
The data is raw and unaudited and the contours give a ‘general’ indication of the spread of rainfall in the region for the month compared to the long term median.
NRC would like to thank MetService and NIWA for making their automatic rainfall data available for the generation of these maps.