Current Climate - January 2012

The first half of January was characterised by easterly and northerly winds, which produced wet and windy weather for areas exposed to the northeast.  In contrast, the second half of the month was very cool, with frequent southerly winds which brought unusually cool air over the country.  For the month as a whole, lower pressures than normal prevailed over New Zealand, as well as to the north and east of the country, producing a rather cool, windy, and unsettled month overall.

Rainfall

Well below normal January rainfall totals (less than half of January normal) were observed in the greater Nelson region, as well as in Blenheim, and on Banks Peninsula. In contrast, it was an extremely wet January from Gore to Queenstown, and across much of the southern half of the North Island.  For the Hokianga, and much of Auckland, Coromandel, and the Waikato, as well as coastal Bay of Plenty, rainfall was close to normal (ranging between 80 and 119 percent of January normal).  Elsewhere, rainfall totals were mostly below normal (between 50 and 79 percent of January normal).  Soil moisture levels for most of the country were close to normal, for this time of year.  Significant soil moisture deficit (more than 110 mm of deficit) was observed by the end of January in eastern areas of the South Island, the Mackenzie basin, central Otago, and parts of the Gisborne region. 

Temperature

Below average temperatures (between 0.5°C and 1.2°C below average) were generally experienced across western regions of the North Island, as well as inland Bay of Plenty, inland Hawkes Bay, Wellington and the Wairarapa, Canterbury, and across most of Fiordland, Westland and Buller.  Elsewhere (generally in the northeast of both islands), mean temperatures for January were close to average (within 0.5°C of the January average).  The nation-wide average temperature in January was 16.4°C (0.7°C below the 1971–2000 January average), using NIWA’s seven-station temperature series which begins in 1909. 

Sunshine

It was a rather cloudy January for the north and west of the North Island, with below normal sunshine totals (between 75 and 90 percent of January normal).  In contrast, it was sunny over the southern half of the South Island, with above normal sunshine totals (between 110 and 125 percent of January normal).  Elsewhere, sunshine totals were generally in the near-normal range. 

Percentage of normal rainfall, January 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 January 2012.