National Climate Summary – December 2006
WEDNESDAY 3 JANUARY 2007
National Climate Summary – December 2006: Rather cool
- Temperature: One of the
coldest Decembers in the last sixty years
- Rainfall:
Well below normal in the north of both islands; above normal
in the east, especially Canterbury
- Sunshine: Sunnier
than normal in the north of both islands
- Wind: More
frequent cold southerlies
December was unusually cool for the time of year, due to more frequent southerly winds. Temperatures were 2 to 3 °C below normal (making it coldest start to December for many years) throughout New Zealand during the first half of the month, with little change during the last two weeks.
For the month, many locations experienced one of their coldest December’s on record. Wellington recorded its coldest December in more than 70 years, while New Plymouth, Wanganui, and Blenheim had their coldest December in at least 60 years. The national average temperature was 13.7 °C (1.9 °C below normal), the lowest for December since 13.4 °C in 2004 and equal with 1946. Rainfall was less than 50 percent (half) of normal in the north of both islands. However, it was quite wet, with at least 200 percent (twice) of normal rainfall, in some eastern parts of the country, especially in Canterbury. A sunny month occurred in parts of Northland, Auckland, Buller, Westland, and Nelson. More anticyclones (‘highs’) predominated in the Australian Bight, extending ridges of high pressure into the South Tasman Sea. Mean sea level pressures were below average northeast of the Chatham Islands. As a result, cold southerlies were more frequent than average over New Zealand.
Other Highlights:
The highest temperature during December 2006 was
31.5 °C recorded at Blenheim Airport on the 12th.
The lowest air temperature for the month was -2.5 °C
recorded at Chateau Ruapehu on the10th.
High rainfall
occurred in Christchurch (74 mm) and over Banks Peninsula on
the 20th, and in South Canterbury (with flooding in
Ashburton) on the 29th.
A hailstorm affected Riwaka
on 1 December, with slight damage occurring to apples in
some orchards.
A wind gust of 148 km/h from the
northwest was recorded at South West Cape on the 7th.
Auckland was the warmest and driest, Christchurch the
wettest, and Wellington the sunniest of the five main
centres. Temperatures were well below normal in all five
main centres. Rainfall was below normal in Auckland and
Hamilton, above normal in Christchurch and Dunedin, and near
normal in Wellington. Sunshine hours were above normal in
Auckland, and near normal in the other
centres.
Temperature: Mean temperatures were 2.0 to 2.4
°C below average in many regions, and more than 2.5 °C
below average in Taupo and parts of Canterbury. Many
locations experienced one of their coldest December’s on
record.
Rainfall: December rainfall totals were less
than 50 percent (half) of normal in parts of Northland,
Waikato, Nelson, and central Marlborough. Rainfall was also
below normal in much of Auckland, Waikato, Bay of Plenty,
Westland, and Southern Lakes. In contrast, rainfall was
about 200 percent (twice) of normal throughout much of
Canterbury. Rainfall was also above normal in parts of
Gisborne, Hawke’s Bay, and East Otago.
Sunshine:
Sunshine hours and/or solar radiation were at least 110
percent of normal in parts of Northland, Auckland, Buller,
Westland, and Nelson. Sunshine hours were below normal in
Manawatu and on the Kaikoura coast.
For further
information, please contact:
Dr Jim Salinger –
Principal Scientist – Climate, NIWA National Climate
Centre, Auckland,
Tel. (09) 375 2053 (work) or (027) 521
9468 (mobile) or (09) 576 9468 (Home)
Stuart Burgess –
Climatologist – NIWA National Climate Centre, Wellington,
Tel. (04) 386 0569
TEMPERATURES WELL BELOW AVERAGE THROUGHOUT NEW ZEALAND
The national average temperature was 13.7 °C (1.9°C below normal), the lowest for December since 13.3 °C in 2004 and equal with 1946. Mean temperatures were 2.0 to 2.4 °C below average in many regions, and more than 2.5 °C below average in Taupo and parts of Canterbury. Many locations experienced one of their coldest December’s on record.
Near or record low
December mean air temperatures were recorded
at:
Location Mean air
temperature
(ºC) Departure
from
Normal Year
Records
began Comments
Kaitaia
Airport 15.6 -2.5 1948 Lowest
Kaikohe
EDR 15.1 -1.9 1973 Equal lowest
Whangarei
Airport 16.6 -1.7 1967 Equal lowest
Warkworth
15.1 -1.9 1972 2nd lowest
Paeroa 15.4 -2.6 1947 2nd
lowest
Auckland,Owairaka 15.4 -2.3 1949 Equal
lowest
Whakatane Airport 15.4 -2.2 1974 2nd
lowest
Rotorua Airport 13.8 -2.3 1964 2nd lowest
Taupo
Airport 12.8 -2.9 1976 Lowest
Aukland,
Mangere 16.0 -2.1 1950 2nd lowest
Auckland
Airport 15.9 -2.2 1962 Lowest
Pukekohe
15.1 -1.9 1970 Lowest
Hamilton
Airport 14.3 -2.3 1970 Lowest
Port Taharoa
15.4 -2.3 1982 2nd lowest
Te Kuiti
14.4 -2.4 1959 Lowest
Taumarunui 13.7 -3.0 1947 2nd
lowest
New Plymouth Airport 13.7 -2.3 1944 Lowest since
1946
Lower Retaruke 13.7 -2.3 1966 2nd
lowest
Castlepoint 13.7 -2.9 1972 Lowest
East Taratahi
13.9 -1.9 1972 2nd lowest
Napier
Airport 15.4 -2.9 1973 2nd
lowest
Whakatu 14.3 -2.9 1982 2nd lowest
Paraparaumu
Airport 14.0 -1.9 1953 Equal lowest
Palmerston North
Airport 13.8 -2.3 1962 Lowest
Palmerston
North 13.5 -2.8 1928 2nd lowest
Wellington,
Kelburn 12.9 -2.4 1928 Lowest
Wellington
Airport 14.6 -1.8 1962 Lowest
Wallaceville
13.5 -2.0 1939 Equal 2nd lowest
Wanganui,Spriggens
Park 14.1 -2.6 1937 Lowest
Hokitika
Airport 12.6 -1.7 1963 3rd lowest
Reefton
13.4 -1.8 1960 Equal 3rd lowest
Nelson, Appleby
13.9 -2.2 1932 2nd lowest
Blenheim
Airport 14.2 -2.1 1941 Lowest
Kaikoura
12.7 -2.6 1963 Lowest
Arthurs
Pass 8.1 -3.1 1978 Lowest
Winchmore 12.3 -2.5 1949 2nd
lowest
Christchurch Airport 13.3 -2.5 1953 2nd
lowest
Timaru Airport 12.2 -2.1 1962 2nd lowest
Tara
Hills 12.2 -2.2 1949 3rd lowest
Clyde 13.2 -2.4 1983 2nd
lowest
Gore EDR 11.0 -2.2 1987 2nd lowest
Dunedin
Airport 12.2 -1.6 1962 Equal 3rd lowest
Raoul
Island 19.6 -1.3 1940 Equal 3rd lowest
RAINFALL WELL
BELOW NORMAL RAINFALL IN THE NORTH OF THE NORTH ISLAND; WELL
ABOVE NORMAL IN CANTERBURY
December rainfall totals were less than 50 percent (half) of normal in parts of Northland, Waikato, Nelson, and central Marlborough, and 75 percent (three quarters) or less of normal in much of AucklandBay of Plenty, Westland, and Southern Lakes. In contrast, rainfall was about 200 percent (twice) of normal throughout much of Canterbury. Rainfall was also above normal, with totals 125 percent (one and a quarter) or more of normal in parts of Gisborne, Hawke’s Bay, and East Otago. Rainfall was near normal elsewhere.
Near or record low December rainfall was
recorded at:
Location December
Rainfall
(mm) Percentage
Of normal Year
Records
began Comments
Kerikeri EWS 22 21 1981 2nd
lowest
Kerikeri Airport 34 28 1978 2nd
lowest
Auckland, Henderson 41 45 1985 3rd lowest
Franz
Josef 309 55 1982 3rd lowest
High December rainfall was
recorded at:
Location December
Rainfall
(mm) Percentage
Of normal Year
Records
began Comments
Winchmore 147 244 1947 3rd
highest
Middlemarch 128 187 2000 Highest
SUNNY IN THE NORTH OF BOTH ISLANDS
Sunshine hours and/or solar radiation were at least 110 percent of normal in parts of Northland, Auckland, Buller, Westland, and Nelson. Sunshine hours were less than 90 percent of normal in Manawatu, and on the Kaikoura coast, and near normal elsewhere.
DECEMBER’S CLIMATE IN THE FIVE MAIN CENTRES
Auckland was the warmest and driest, Christchurch the wettest, and Wellington the sunniest of the five main centres. Temperatures were well below normal in all five main centres. Rainfall was below normal in Auckland and Hamilton, above normal in Christchurch and Dunedin, and near normal in Wellington. Sunshine hours were above normal in Auckland, and near normal in the other centres.
Location Dec.
Mean
Temp.
(°C) Dep.
from
normal
(°C) Dec.
rainfall
(mm) %
of
Normal Dec.
Sunshine
(hours) %
of
Normal
Auckland 16.0 -2.1 Well below normal 45a
49 Below normal 232 111 Above
normal
Hamilton 14.4 -2.4 Well below normal 51 55 Below
normal 218 98 Near normal
Wellington 12.7 -2.6 Well below
normal 93 109 Near normal 241 106 Near
normal
Christchurch 13.7 -2.3 Well below normal 123
249 Well above normal 208b 94 Near
normal
Dunedin 12.2 c
-1.6 Well below
normal 98 121 Above normal 167 99 Near normal
a Owairaka
b Christchurch Airport c Dunedin Airport
HIGHLIGHTS AND EXTREME EVENTS
Temperature
The highest temperature during December 2006 was 31.5
°C recorded at Blenheim Airport on the 12th, during hot dry
northwesterly conditions, which also affected Canterbury.
The lowest air temperature for the month was -2.5 °C
recorded at Chateau Ruapehu on the10th.
Record low
December minimum air temperatures were recorded
at:
Location Minimum
air temperature
(ºC) Date
of occurrence Year
Records
began
Pukekohe 4.4 10
Dec. 1970
Christchurch Airport 0.1 2
Dec. 1953
Manapouri, West Arm -0.6 1 Dec. 1996
High
rainfall
There were several high rainfall events, with at
least 50 mm in 24 hours (the 29 December event produced
flooding), during December. These were:
Date Region and
location Rainfall
2 Dec. Fiordland Milford Sound (53
mm)
12 Dec. Fiordland Milford Sound (51 mm)
16
Dec. Southern Alps Mt Cook (56 mm)
19 Dec. Coromandel,
Southland Whitianga Airport (76 mm),
Secretary Island
(85 mm)
20 Dec. Canterbury,
Banks
Peninsula Christchurch, Kyle St. (74 mm),
Le Bons Bay (52
mm)
25-27 Dec. West Coast Milford Sound (232 mm over
2-days)
29 Dec. South Canterbury Ashburton (83 mm)
Snowfall
Arthur’s Pass was closed due to snowfall over
the night of 30 November/1 December. Sleet and snow were
observed at Porters Pass on 30 December.
Hailstorm
A hailstorm hit Riwaka at about 2pm on 1
December, with slight damage occurring to apples in some
orchards.
High winds
A wind gust of 148 km/h from
the northwest was recorded at South West Cape on the
7th.
ENDS