Current Climate - August 2012

August 2012 was dominated by more northeast winds than normal over New Zealand, squeezed between higher than normal pressures southeast of the country, and lower pressures than usual over the mid Tasman Sea. The northeasterly winds also produced a very large contrast in rainfall across the Southern Alps. 

Rainfall

It was an extremely wet August (with more than 200 percent of August normal rainfall recorded) in the north and east of the South Island, namely Nelson, Marlborough, Canterbury and north Otago.  Some areas received treble (300 percent of) August normal rainfall, such as in Timaru, which recorded its third wettest August since 1881.  In contrast, it was very dry over the west and south of the South Island (with less than 50 percent of August normal rainfall south of Westport), showing the effects of prevailing northeasterly winds.   Record low or near-record low August rainfall was seen across Southland.

For the north and east of the North Island, it was a rather wet August.  Above normal rainfall was experienced in Northland, Auckland, Coromandel, Gisborne, and parts of the Bay of Plenty, Hawkes Bay and the Wairarapa.  Elsewhere in the North Island (and for the Buller region of the South Island), near normal rainfall was generally recorded.

Temperature

The frequent northeast winds during the month produced an unusually mild August.  Well above average temperatures  were observed in Nelson/Marlborough, along the West Coast of the South Island, in Southland and in Central Otago, around Christchurch, Timaru, and Oamaru, in parts of Hawkes Bay, in the Firth of Thames, and between Ohakune to Palmerston North.   It was the warmest August on record for Leigh, Ohakune, Westport, Haast, Milford Sound, Nelson, and Secretary Island.  Elsewhere, temperatures were typically above average, too.  The nation-wide average temperature in August 2012 was 9.9°C (1.2°C above the 1971-2000 August average), using NIWA’s seven-station temperature series which begins in 1909.

Sunshine

It was a very sunny August for the south and west of the South Island, reflecting the high frequency of northeasterly winds during the month.  It was the sunniest August on record for Queenstown, and the second-sunniest August on record for Balclutha.  It was also a sunnier than usual August for the western North Island between Auckland and Taumarunui.  In contrast, it was a rather dull August between Taranaki and Wellington, for Nelson and Marlborough, and the eastern South Island.  It was the cloudiest August on record at Takaka.  Elsewhere, sunshine totals were generally near normal.   


Percentage of normal rainfall for August 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 August 2012.