Temperatures: Coldest August overall in more than ten years. Especially cold in Canterbury, Otago and Southland
Rainfall: Well above average in the Wairarapa, and coastal Canterbury, Otago and southland; below average in Northland, Auckland, Bay of Plenty, Nelson and Marlborough
Sunshine: Record high hours in Auckland; well above average in Northland, Waikato King Country, Taranaki, Manawatu, Buller and Westland, with lower than normal totals in the Wairarapa and Canterbury
A convergence of intense depressions (‘lows’) around the Chatham Islands led to the extremes of cold, high rainfall, hail, snow and wind which enveloped New Zealand in August. These produced storm force southerlies, which brought wintry conditions to many areas. The prolonged period of storms from 11 – 30th August produced two high rainfall events producing floods, two severe hail storms, four heavy snowfall events to low levels, record ground frosts, a destructive tornado and the worst southerly wind storm to batter the Wellington area in more than a decade. Nationally, this was the coldest August since 1992. Kelburn in Wellington recorded 7 consecutive days from 23-29 August with maximum temperatures of 9.0°C or less, making this the longest cold spell there since July 1981. Temperatures were well below average throughout much of the South Island. It was very wet, with about 200 percent (twice) of average rainfall, in many eastern regions from Wairarapa to Southland. In contrast, rainfall was below average in northern regions of both Islands. Record sunshine occurred in Auckland and hours were well above average in the north and west of the North Island and Westland. Sunshine was less than average in the east from southern Wairarapa to the Southern Lakes. Depressions (‘lows’) were very much more frequent than average east of New Zealand, often centred near the Chatham Islands, resulting in long periods of cold southerlies in many areas.
Highlights
- The highest August 2004 temperature was 20.2°C, recorded at Darfield on the 12th. The lowest temperature for the month was -12.0°C, recorded at Fairlie on the 16th.
- Auckland was the sunniest and driest of the four main centres. Rainfall was below average in Auckland, near average in Wellington, and well above average in Christchurch and Dunedin. Temperatures were below average in all four main centres. Sunshine totals were a record in Auckland, above normal in Wellington, near normal in Dunedin, and below normal in Christchurch.
Temperatures
Mean temperatures below average almost everywhere, and especially in the South Island where they were at least 1.5°C below average in most southern and eastern regions. Temperature were near average only in Gisborne and Hawke’s Bay. The national average of 7.9°C was 0.8°C below average.
Rainfall
It was very wet, with about 200 percent (twice) of average rainfall, in parts of Wairarapa, Canterbury, Otago, and coastal Southland. Rainfall was also above average in Waikato, Wanganui, Ruapehu, southern Hawke’s Bay, the Kapiti coast, the Hutt Valley, Nelson Lakes, Fiordland, and inland Southland. In contrast rainfall was less than 50 percent (half) of average in inland Bay of Plenty, and also below average in Northland, Auckland, Coromandel, coastal Bay of Plenty, Nelson, and much of Marlborough.
Sunshine
Monthly sunshine totals were well above average in Northland, Auckland, Waikato, Taranaki, King Country, Manawatu, and Westland. However, totals were below average in the Wairarapa, north Canterbury, and the Southern Lakes.
Full report
Full details of August 2004 summary.
For further information, please contact:
Dr Jim Salinger – Principal Scientist, Climate NIWA National Climate Centre – Auckland Phone +64 9 375 2053 [email protected]
Stuart Burgess – Climatologist NIWA National Climate Centre – Wellington Phone +64 4 386 0569 [email protected]
Geoff Baird – Communications Manager Phone +64 4 386 0543 [email protected]
Acknowledgement of NIWA as the source is required.