Sunday, 6 March 2005
Temperature swings: A very cold December and a very warm February Soil Moisture: Severe or significant deficits throughout much of the North Island, and the north and east of the South Island during mid and late summer Rainfall: Well above average rainfall in southern Wairarapa and the east from mid Canterbury to Southland; below average rainfall in eastern Bay of Plenty Sunshine: above average in the east of the North Island
Temperature extremes by day and by month were features of the 2004-05 summer which turned out to be 0.3°C below normal over the three month period with an average of 16.3°C. Summer temperatures went from one extreme to the other. December, with frequent southerlies, was the coldest since 1945 and fifth coldest on record overall. January was warmer, but temperatures were still 0.5°C below normal. On the other hand, February 2005 was very much warmer, with more frequent northeasterlies; being the 8th warmest in the historical record. The first 10-days of February were very hot, with maximum temperatures of 30°C or more in many locations throughout New Zealand, and 35°C or more in sheltered inland areas of the South Island. Summer rainfall was well above average in parts of southern Wairarapa, and in the eastern South Island from mid Canterbury to Southland, Timaru recording its wettest summer in almost 50-years. Relatively low rainfall occurred in eastern Bay of Plenty. Severe or significant soil moisture deficits occurred throughout much of the North Island and the north and east of the South Island during January and February. The summer was sunnier than average in the east of the North Island. The overall summer climate pattern was dominated by more depressions ('lows') east of the South Island with south westerlies over the North Island and south easterlies over southern New Zealand.
Highlights
- The highest temperature of the summer occurred during the February heat wave and was 38.7°C recorded at Alexandra on the 4th (the highest temperature there for any month, in records back to 1929). This is only one a few occasions when temperatures in New Zealand have exceeded the old 100°F (37.8°C). Ground frost occurred in December in inland sheltered areas of the North Island, including Hawke’s Bay, and Manawatu, and on several days during the month in many locations in the South Island. The lowest temperature for the summer was -3.7°C, recorded at Wreys Bush (Southland) on the 20th of December.
- An unseasonably cold outbreak brought gale force southerlies to exposed southern and eastern areas of New Zealand over the 18th-19th of December, and thunderstorms with hail to several districts, along with snowfall in the high country of both islands.
- A damaging tornado affected parts of Auckland on the 22nd of December.
- Fog resulted in the closure of Wellington airport affecting thousands of travellers over 2-6 February.
- Rainfall resulted in flash floods on the Kapiti coast on the 5th of January. Localised high, short period rainfall also affected eastern areas of Southland on the same day. High rainfall also resulted in flooding, landslips, damage, and stock losses in South and West Otago over the 7th-8th of January. Heavy rainfall on the afternoon of the 17th of January resulted in flooding in Dunedin. Torrential rainfall occurred in Dunedin on the 7th of February, with flooding affecting many houses and shops. Heavy rainfall also occurred in Temuka over the 13-14th of February, resulting in surface flooding.
- Of the four main centres Wellington was, by far, the sunniest and Christchurch easily the driest. Rainfall was near average in Auckland, and above average in the other main centres. Temperatures were near average in Wellington, but below average in the three other main centres. Sunshine hours were below average in Dunedin, and near average in Auckland, Wellington and Christchurch.
Temperature
Mean temperatures were below average overall in many regions, and 1.0°C or more below average in parts of Auckland, King Country, coastal Wairarapa, coastal Otago, and inland Southland. However, they were above average in parts of central Wairarapa.
Rainfall
Summer rainfall was well above average in southern Wairarapa and in much of the eastern South Island, from mid Canterbury to Southland. In contrast rainfall was below average in eastern Bay of Plenty. Rainfall was near average elsewhere.
Sunshine
Sunshine hours were above average in Wairarapa, and slightly above average in other eastern North Island regions. Totals were below average in Waikato, and coastal Otago.
Full report
Full details of Summer 2004–05 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.
