Winter 2006: Wild in the lower North Island, exceptional snowstorms in the east of the South Island, but quite benign in the north of both islands. New high sunshine records in places.
- Rainfall: Wet in the southern half of the North Island, especially Wanganui, Wairarapa, and Wellington; relatively dry in the north of both islands, and Otago
- Temperature: Below normal in the north and west of the North Island, Buller, South Canterbury and east Otago; near normal elsewhere
- Sunshine: Extremely sunny for winter with record winter sunshine in parts of the north and west of the North Island and the southeast of the South Island
This was a winter of extremes in parts of New Zealand, with exceptional snowstorms in the east of the South Island, significant snowfall also in the central North Island, severe floods and landslips in the lower North Island, and damaging winds. In contrast it was also very sunny in many areas and dry in the north of both islands and Otago.
Winter rainfall was at least 150 percent (one and a half) of normal in Wanganui and Wairarapa, and parts of Wellington (including Kapiti). Soil moisture in these regions was already at field capacity (nearly saturated) at the start of June. In contrast, winter rainfall was only about 50 percent (half) of normal in parts of Northland and Otago, and below normal in Thames-Coromandel, Western Bay of Plenty, much of Auckland, Nelson, and much of Marlborough. The national average winter temperature of 8.1°C was close to normal, being 0.2°C below average. This was lowest since 1997, as many recent winters have been much warmer than normal. Seasonal mean temperatures were below normal throughout much of the north and west of the North Island from Northland to Horowhenua, as well as Buller, South Canterbury and Otago, but near normal elsewhere. This winter was also unusual because June was an exceptionally cold month, the coldest month of the winter. Temperatures, for New Zealand as a whole, were above or near normal for the remainder of winter. Sunshine hours for winter were extremely high in the north and west of the North Island from Northland to Wellington, and in the east of the South Island from inland South Canterbury to Southland, with some centres recording their sunniest winter on record. The overall winter climate pattern was dominated by more frequent anticyclones ('highs') than usual in the Australian Bight, often extending into Tasman Sea. This pattern produced frequent southerly winds over the North Island and southwesterlies over southern New Zealand.
Major Highlights
- The highest temperature recorded during the winter was 21.8°C recorded at Timaru Airport on 29 August. The lowest air temperatures for the winter were -14.0°C recorded Tara Hills, Omarama on 14 June and Fairlie on 28 June. The minimum air temperatures were -10°C or lower in parts in inland South Canterbury and/or North Otago, on nine days between 14 and 29 June.
- High rainfall events were frequent throughout the winter, occurring on at least eight occasions; the worst event occurring over 4-6 July in the Wairarapa, Wanganui and Wellington regions. Over 300 mm was reported within 24 hours in parts of South Wairarapa, where people had to be evacuated from their homes. Martinborough was isolated by floodwaters, and surface flooding which also affected Greytown and Carterton. In Wairarapa, more than 50 roads were closed due to flooding or landslips. The settlement of Mangamahu (northeast of Wanganui) was isolated by the collapse of the Mangawhero river bridge. A house in Wanganui was struck by a landslide, with two others later affected in Hunterville.
- The highest wind gust for the winter was 167 km/h from the northwest was recorded at Southwest Cape (Stewart Island) on 28 August. A tornado damaged property in Greymouth on 11 June, and also destroyed property in the Waikato on the 12 July. Northwest gales buffeted the North Island on 12 June, with damage and power outages in parts of Auckland, Thames-Coromandel, Waikato, and the Marlborough Sounds. Trees fell in Tauranga, with other wind damage in Kaitoke and Nelson. Power lines were damaged by wind in Taranaki, Bay of Plenty, and Gisborne, on 19 June, with power cut to thousands of residents. Several iron roofs were damaged in Gisborne, and New Plymouth.
- The worst of the winter snowfall events occurred in Canterbury over the night of 11/12 June, especially in the south, snow settling to depths of 75-90cm around Fairlie and Burkes Pass, almost 40cm in Ashburton, and more than 20cm in Timaru, some remaining in some inland areas until the 27th. Extended power cuts occurred throughout much of South Canterbury, due to broken power lines and poles. The roofs of several buildings also collapsed, due to the weight of snow. Many motorists were stranded in the snow, and many roads closed. Southerlies spread over the North Island over 20-22 June, bringing heavy snowfall down to 500m, affecting the Desert Road, and townships of Waiouru, Ohakune, National Park, and the outskirts of Taupo, with many roads closed, including those to the east coast. Two buses slid off icy roads in the Central North Island, and nearly 100 cars were stranded in the snow.
Of the five main centres, Wellington was the wettest, Dunedin easily the driest and Auckland the sunniest. Rainfall was above average in Wellington and Christchurch, below average in Auckland and Dunedin, and near average in the other main centres. Temperatures were near average in Wellington, but below average in the four other main centres. Winter sunshine hours were above average in all five cities, with Dunedin recording its sunniest winter on record.
Rainfall
Winter rainfall was at least 150 percent (one and a half) of normal in Wanganui and Wairarapa, and parts of Wellington (includes Kapiti), and also above normal in Taupo, the Gisborne high country, Hawke’s Bay, Manawatu, and the mid Canterbury coast. In contrast, winter rainfall was below normal in Northland, Thames-Coromandel, Western Bay of Plenty, much of Auckland, Nelson, and much of Marlborough and Otago.
Temperature
Seasonal mean temperatures were near normal for New Zealand overall. However, they were at least 0.5 °C below normal in much of the north and west of the North Island from Northland to Horowhenua, and also below normal in Buller, South Canterbury and east Otago.
Sunshine
Winter sunshine hours were at least 120 percent of normal in the north and west of the North Island from Northland to Wellington, and in the east of the South Island from inland South Canterbury to Southland. It was also sunny, with at least 110 percent of normal hours in most other regions. In Dargaville, Hamilton, New Plymouth, Dunedin and Invercargill it was the sunniest winter on record.
Full report
- Full details of the Winter 2006 Climate 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.