Outlook and outcome – March 2004 to May 2004

Rainfall was lower than predicted in the west of the North and South Islands, in Northland, and in parts of the east and south of the North Island. In other areas, rainfall was normal or below normal as expected.

Air temperatures were average or below average as predicted in most places, although it was cooler than expected in the north and east of the North Island.

River flows were expected to be normal or above normal in western regions, normal or below normal in the east of the South Island, and near normal elsewhere. Flows were generally normal or above normal in western regions, and near normal elsewhere.


The outcome maps shown here give the tercile rankings of the rainfall totals and mean temperatures that eventuated for these months. Terciles were obtained by dividing ranked March to May data from the past 30 years into three groups of equal frequency (lower, middle and upper one-third values) and assigning the data for the present year to the appropriate group. (Click to enlarge)

As an approximate guide, middle tercile rainfalls often range from 80 to 115% of the historical average. Middle tercile air temperatures typically occur in the range of the average plus or minus 0.5°C.