Warm but extreme weather in December
Tornado damage in west Auckland (Photo: Dylan Moran/3 News)
December was a month of extremes, with record-breaking warm temperatures, a deadly tornado and flooding in some areas.
NIWA statistics show much of the country had above average warm weather. December 2012 was warmer than December 2011, with the average temperature rising from 15.8degC to 16.7degC.
The North Island, Nelson, and the east of the South Island had temperatures 1.2degC above the December average. Other parts of the country had temperatures between 0.5degC and 1.2degC above average.
The highest temperature recorded in December was 34.5degC in Gisborne on December 19. This is compared to December 2011’s monthly high of 31.3degC in Alexandra on December 13.
Kaikohe, Port Taharoa, New Plymouth, Martinborough, Ngawi, Palmerston North, Levin, Wellington Airport, Wallaceville, Ohakune, Wanganui, Takaka, Reefton, Motueka and Nelson broke their records for the highest December temperature – most of them recorded on Christmas Eve or Christmas Day.
Kerikeri and Motu recorded their lowest temperatures so far for December.
“The fact that a number of records were set in regards to temperature, that does say the month was quite warm,” says Niwa principal climate scientist Andrew Tait.
He says the warm weather was brought by ex-tropical cyclone Evan.
There was also a lot of sun, with the South Island and eastern North Island having 120 percent of normal amounts for December. However the northern half of the North Island only had around 75 to 90 percent of normal sunshine.
Winds were also extreme in December. A tornado in Auckland killed and injured people, while a twister in Cromwell and strong winds in Featherston, Wellington and Nelson damaged property and trees. December wind gust records were broken in Whenuapai, Rotorua Airport and Castle Point.
Some areas were very wet and others very dry in December. Rainfall was higher than normal in the far north and deep south of New Zealand, with flooding in Auckland, Rotorua, Christchurch and Dunedin. However Gisborne, Hawkes Bay, Wairarapa, Nelson, Canterbury, Otago and central Southland, had only 50 percent of normal December rainfall.
“The weather system that we had in December was quite a large variety,” says Dr Tait.
“We did get wind, we did get tornados, we did get flooding and we did get very, very low rainfall.”