Current Climate - March 2012

March was characterised by higher pressures than usual to the east of the Chatham Islands, and more lows than normal to the north of the North Island.  This produced more easterly winds than usual over the country.  The frequent easterly winds resulted in an extremely cool March for eastern areas of both Islands, and produced wetter conditions for many areas of the North Island and some eastern South Island regions.  It was also much cloudier than usual for the northeast of the North Island, as well as the northern South Island.

Rainfall

March rainfall totals were at least 200 percent (double) normal for Northland, north Auckland, and for eastern parts of the North Island.  It was also a wet March (with at least 120 percent of March normal) across most of the remainder of the North Island, as well as for Kaikoura, north Canterbury and Otago.  In contrast, it was rather dry for the West Coast of the South Island, Fiordland, Nelson City, Christchurch, south Canterbury, as well as between Wanganui and Palmerston North, and around Taupo. In Southland, rainfall was close to normal. Soil moisture levels at the end of March were well above normal for much of the North Island as well as in Otago, but were closer to normal elsewhere. An exception was between Wanganui and Palmerston North, where soils were somewhat drier than is usual at this time of year.

Temperature

Mean temperatures for March were well below average (more than 1.2°C below average) for much of the south and east of the South Island, as well as Wellington, the Wairarapa, southern Hawkes Bay, and the Central Plateau.  Elsewhere, March temperatures were generally below average (between 0.5°C and 1.2°C below average), with the exceptions of Westland and Fiordland, where near average temperatures were experienced (within 0.5°C of average). The nation-wide average temperature in March was 14.6°C (1.2°C below the 1971–2000 March average), using NIWA’s seven-station temperature series which begins in 1909. 

Sunshine

The effect of the prevailing easterly winds during March was evident in the observed sunshine totals.  It was a very cloudy month for the north and east of the North Island (Northland, Auckland, Coromandel, Gisborne, Hawkes Bay, Wellington and the Wairarapa), as well as for Nelson/Marlborough.  In contrast, it was an extremely sunny March for Otago and Southland.  Sunshine hours were closer to normal elsewhere.

Percentage of normal rainfall, March 2012
End of month water balance in the pasture root zone for an average soil type, where the available water capacity is 150mm.
Departure from average air temperature for March 2012.