April's climate

New Zealand climate in April

Rainfall (click to enlarge).

Temperature (click to enlarge).

April was a relatively dry month overall, especially over the North Island and the north and west of the South Island, with less than 50% of normal rainfall in many areas. The month was dominated by anticyclones to the west and winds from the southerly sector, which produced cooler than normal conditions for many.

For more information on the climate in April 2007, visit the climate summaries page at www.niwascience.co.nz/ncc/cs/mclimsum_07_04

End of month rainfall lifted soil moisture levels

Soil moisture (click to enlarge).

Rainfall late in April brought some relief to dry soils in many areas, although soil moisture deficits of about 110 mm persisted in Hawke’s Bay, central Marlborough and Central Otago.

 

Mostly below normal catchment yields

River flows (click to enlarge).

April streamflows were normal in the far north, and generally below normal elsewhere.

February to April: the climate we predicted and what happened

(click to enlarge).

Rainfall

Rainfall was normal or below normal as predicted in the east and north of the North Island, apart from wetter than expected conditions in Northland. Elsewhere conditions were mostly drier than expected.


(click to enlarge).

Air temperature

Air temperatures were higher than predicted in the south and west of the South Island, but near normal as expected elsewhere.


(click to enlarge).

River flows

Streamflows were above normal in the far north and mostly below normal elsewhere. Catchment yields were generally lower than predicted in the South Island, and southwest North Island.


The three outcome maps give the tercile rankings of the rainfall totals, mean air temperatures, and mean river flows that eventuated from February to April, in comparison with the forecast conditions.

As an approximate guide, middle tercile rainfalls typically range from 80 to 115% of the historical normal, and middle tercile temperatures range about the average by plus or minus 0.5 °C.