An unusually mild August.
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Temperature |
Frequent northeast winds produced an unusually mild August across the country. |
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Rainfall |
A large contrast in rainfall seen across the Southern Alps. More than double normal August rainfall seen in the north and east of the South Island. In contrast, it was extremely dry over the west and south, with low rainfall records broken in Southland. For the north and east of the North Island, it was also a rather wet August, but totals were close to normal in the western North Island. |
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Sunshine |
Extremely sunny over southwest New Zealand, and rather sunny between Auckland and Taumarunui. In contrast, very cloudy in the north and east of the South Island, and from Taranaki to Wellington. |
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Soil moisture |
At the end of August, below normal soil moisture levels for the southwest South Island. Above normal levels for the Kaikoura Coast and south Canterbury. |
Overview
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 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.
The northeasterly winds also produced a very large contrast in rainfall across the Southern Alps.
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.
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.
Further Highlights:
- The highest temperature was 22.7°C, observed at Christchurch on 26 August.
- The lowest temperature was -5.3°C, recorded at Ranfurly on 23 August.
- The highest 1-day rainfall experienced was 198 mm at Akaroa on 12 August.
- The highest gust recorded was 135 km/hr at Puysegur Point, Fiordland, on 25 August.
- Of the six main centres in August 2012, Auckland was the warmest and sunniest, Tauranga the wettest, Christchurch was the driest, and Dunedin the coolest and cloudiest.
Full report
Full details of the August 2012 climate summary (PDF 539 KB)
Climate statistics table
Climate statistics for August 2012 (PDF 80 KB)
For further information, please contact:
Ms Georgina Griffiths – Climate Scientist – NIWA National Climate Centre, Auckland
Tel. 09 375 4506 (office) or 027 293 6545 (mobile)
Dr Mike Revell – Principal Scientist, Meteorology and Remote Sensing, NIWA Wellington
Tel. 04 386 0328