Current climate: March 2017

March 2017 was characterised by higher than normal atmospheric pressure over and to the south and west of the South Island, and to the northeast of the North Island, combined with lower than normal pressure to the northwest of New Zealand and far to the southeast of the country. This pressure pattern resulted in a predominant wind flow from the northwest over the North Island, bringing with it moist tropical airmasses and record-high rainfall for the upper North Island.

Rainfall

Significant rainfall totals were experienced for the upper North Island, with over 300% of normal March rainfall recorded in some places. Other locations recorded over 200% of normal March rainfall. The remainder of the North Island had a wet month, with most locations recording above normal rainfall or more (>120% of normal March rainfall). Parts of the northern and eastern South Island also recorded above normal or well above normal (>149% of March normal) rainfall. In contrast, the west and south of the South Island was much drier – some locations recorded well below normal rainfall (<50% of March normal) and many locations recorded below normal rainfall (50-79% of normal).

Temperature

The North Island experienced well above average (>1.20°C above average) or above average (0.51 to 1.20°C above average) temperatures. The South Island was an island of two halves, with the north and west recording above or well above average temperatures and the south and east recording near (-0.50 to 0.50°C of average) or below average (-1.20 to -0.51°C below average) temperatures.

Sunshine

Below normal (75-89% of normal) or well below normal (<75% of normal) sunshine hours for most of the North Island and parts of the northern South Island. In contrast, parts of Otago and Southland recorded well above normal (>125% of normal) sunshine.

Soil Moisture

As at 1 April 2017, soils in the upper half of the North Island were much wetter than normal for the time of year, as well as around Wellington, northern Tasman-Nelson and part of the coastal Ashburton District. Soils were much drier than normal for the time of year for Southland, Stewart Island, Queenstown-Lakes, north Canterbury and Marlborough.

Departure from average air temperature for March 2017.
End of month water balance in the pasture root zone for an average soil type where the available water capacity is taken to be 150 mm.
Percentage of normal rainfall for March 2017.