February 2005

Temperature: Extreme warmth – extended heat-wave – 8th warmest February on record

Soil moisture: Severe or significant deficits throughout much of the North Island, and the north and east of the South Island

Rainfall: Below average in many eastern areas – above average in north Westland and the east of the South Island, from south Canterbury to Southland

Sunshine: Above average in the west of the South Island and southern half of the North Island

February 2005 was one of the warmest on 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 temperatures of 35°C or more in sheltered inland areas of the South Island. For the month, the national average temperature of 18.6°C was 1.3°C above normal, and 8th highest since reliable measurements dating back to the mid 1860s. Rainfall was below average over much of the North Island, especially parts of Hawke’s Bay, Wairarapa, inland and eastern Bay of Plenty, Gisborne, and Manawatu. It was also drier than average in Wanganui, Kapiti, south Westland, Marlborough, and north Canterbury. Severe soil moisture deficits occurred in parts of Bay of Plenty, Gisborne, Hawke’s Bay, Wairarapa, Wanganui, Marlborough, and north Canterbury, and were significant in parts of Northland, Auckland, Thames, Taupo, Manawatu, Horowhenua, Kapiti, Wellington, Nelson. Water restrictions occurred in Taranaki, with total bans on sprinklers, irrigation systems and unattended hoses. Rainfall was above average in parts of Northland, King Country, Eastland, north Westland, Banks Peninsula, south Canterbury, Otago, and Southland. It was sunnier than average in the west of the South Island and the southern half of the North Island but sunshine hours were below average in south Taranaki, and inland south Canterbury. Anticyclones (‘highs’) were often centred to the east of New Zealand, with depressions in the south Tasman Sea. This pattern resulted in more frequent north easterlies than average over much of New Zealand.

Highlights

  • The highest temperatures during the February 2005 heat wave was 38.7°C recorded at Alexandra on the 5th (the highest temperature there for any month, in records back to 1929). This is only one of a few occasions when temperatures in New Zealand have exceeded 100°F (37.8°C).
  • The lowest temperature for the month was 1.8°C, recorded at Ettrick (Central Otago) on the 18th. This was the lowest February temperature there since measurements commenced in 1971.
  • Thunderstorms and brief, but torrential rainfall occurred in Dunedin on the 7th, with flooding affecting many houses and shops. Heavy rainfall, totalling at least 100 mm, occurred in Temuka over the 13-14th, resulting in surface flooding, and a temporary closure of SH1 south of Timaru.
  • Persistent fog resulted in the closure of Wellington Airport and disruption of about 250 flights affecting 1000s of travellers from 2-4 February.
  • Of the four main centres Wellington was the sunniest and Christchurch the driest. Rainfall was above average in Dunedin, and below average in the other main centres. Temperatures were above average in all four centres, especially Wellington and Christchurch. Sunshine hours were above average in Wellington, and below average in Dunedin.

Rainfall

Rainfall was less than 25 percent of normal in parts of Hawke’s Bay, and less than 50 percent of normal in inland and eastern Bay of Plenty, Gisborne, Manawatu, Wairarapa. It was also drier than average in western Bay of Plenty, Ruapehu, Wanganui, Horowhenua, Kapiti, Wellington, south Westland, Marlborough, and north Canterbury. Above average rainfall occurred in parts of Northland, King Country, Eastland, north Westland, Banks Peninsula, south Canterbury, Otago, and Southland.

Temperature

Mean temperatures were about 1.5°C above average in many regions, but more than 2.0°C above average in parts of the southern half of the North Island and eastern parts of the South Island from Canterbury to Otago.

Sunshine

Sunshine hours were above average in north Westland, Manawatu, Kapiti, Wellington, and Wairarapa. However, they were below average in south Taranaki, and inland south Canterbury.

Full report

Full details of February 2005 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.