January 2004

Temperatures: Warm, especially in the east

Rainfall: Dry in parts of Otago and Southland, the Christchurch area and central Marlborough; well above average rainfall in Wairarapa, Hawke’s Bay, Wellington, parts of Northland, the Southern Alps and North Otago

Soil moisture: Significant deficits in parts of eastern Otago, the Christchurch area and central Marlborough

Sunshine: Sunny in the north and east of the North Island, and the south of the South Island; less sunshine than normal in the southwest of the North Island

January was very warm overall, with above normal temperatures in most regions, especially in the east where it was very warm from Wairarapa to Southland. Continuing dry conditions occurred in parts of Otago and Southland, in the Christchurch area and central Marlborough, where soil moisture deficits are significant. However useful rainfall, particularly in the last week, brought relief to dry soils in Wairarapa, Northland, and other areas in the east of the South Island. Rainfall was well above average in parts of Northland, the Wairarapa, Hawke’s Bay, Wellington, the Southern Alps and parts of North Otago. Sunshine totals were above normal in the north and east of the North Island and in the south of the South Island. However, there was less sunshine than normal in the southwest of the North Island. The January climate patterns were associated with more frequent anticyclones (‘highs’) than usual to the north of the North Island, and to the far southeast of New Zealand, with lows in the western Tasman Sea. These produced more frequent easterlies over the North Island and northeasterlies over the South Island.

Highlights

• The highest January 2004 temperature was 38.4°C, recorded at Darfield on the 1^st; equal to the highest January temperature on record for the South Island, and second only to 38.9°C recorded in Ruatoria in the North Island on 11 January 1979. Hanmer Forest recorded 7 days between 1 and 17 January with maximum temperatures exceeding 30°C. The lowest temperature for the month was –0.2°C, recorded at Manapouri Airport on the 21^st.
• Significant rainfall and gale force southerlies occurred over the lower North Island between the 18^th and 23^rd, with heavy falls, totalling up to 100 mm in Wairarapa on the 20^th. The severe gales and high seas resulted in the cancellation of fast-ferry sailings through Cook Strait for two days.
• High rainfall totalling 150 to 200 mm occurred in parts of Northland on the 29-30^th. Rainfall totalling 74 mm was measured at St Bathans (Otago) on the 30^th, with reports of flash flooding in Wanaka.
• Of the four main centres, Christchurch was the driest, and Auckland the sunniest and warmest. It was wet in Wellington and Auckland, and below average rainfall occurred in the other two centres. Temperatures were above average in all four centres. Sunshine hours were below normal in Wellington, and near normal in Auckland, Christchurch, and Dunedin.

Temperature

Mean temperatures were above normal over much of New Zealand, being 1.0 to 2.0°C above average in most eastern districts from Wairarapa to Southland. The January national average temperature of 18.3°C was 1.2°C above normal, the warmest since January 1999, and the 11^th warmest January since reliable measurements commenced in the 1850s.

Rainfall

Rainfall was below average in parts of Otago and Southland, the Christchurch area including Bank’s Peninsula and central Marlborough. About twice the average January rainfall occurred in parts of Hawke’s Bay, Wairarapa, Wellington, the Southern Alps and parts of North Otago.

Sunshine

Sunshine totals were above normal in Auckland, Bay of Plenty, Gisborne, Hawke’s Bay, and Southland. Sunshine was below normal in Taranaki, Manawatu, and Wellington.

Warm, especially in the east

Mean temperatures were at least 0.5°C above normal over much of New Zealand, and 1.0 to 2.0°C above average in most eastern districts from Wairarapa to Southland. The national average temperature was 18.3°C, 1.2°C above normal.

Well above average January mean air temperatures were recorded at:

Location	Mean temperature	Departure from average (°C)	Records began	Comments
Chateau, Ruapehu	14.4	+1.9	1930	2nd highest
Ohakune	16.7	+2.0	1994	2nd highest
East Taratahi	19.8	+2.6	1973	2nd highest
Farewell Spit	19.3	+2.0	1971	3rd equal highest
Motueka	19.0	+1.5	1957	2nd equal highest
Nelson Airport	19.2	+1.5	1944	2nd equal highest
Blenheim Airport	19.8	+1.8	1941	2nd equal highest
Rangiora	18.1	+1.4	1965	2nd equal highest
Lincoln	18.3	+1.5	1881	Well above average
Dunedin Airport	16.7	+1.7	1963	2nd equal highest

Mean daily maximum temperatures were almost 4°C above normal in inland parts of Wairarapa, and 2 to 3°C above average in parts of central Marlborough and Otago.

Record high January mean daily maximum air temperatures were recorded at:

Location	Mean daily maximum temperature	Departure from average (°C)	Records began	Comments
East Taratahi	26.6	+3.5	1973	Highest
Dunedin Airport	23.6	+2.8	1963	Highest

Dry in Otago and Southland, the Christchurch area and Central Marlborough

Rainfall was 50 percent (half) or less of average in parts of Southland, the Christchurch area including Bank’s Peninsula and central Marlborough and 75 percent (three quarters) of average in the remainder of Southland, Otago, and Marlborough.

Record low January rainfall was recorded at:

Location	January rainfall (mm)	Percentage of normal	Year Records began	Comments
Lumsden	45	51	1986	Lowest

Well above average rainfall in Wairarapa, Hawke’s bay, Wellington, The Southern Alps and North Otago

Above well average rainfall occurred in parts of Northland, Hawke’s Bay, Wairarapa, Wellington, and the Southern Alps and North Otago, most with over 200 percent (twice) of average January totals in places. Rainfall was near average elsewhere.

High January rainfall was recorded at:

Location	January rainfall (mm)	Percentage of normal	Year Records began	Comments
Kaitaia	174	205	1986	3rd highest
Waione	174	238	1992	Highest
Castlepoint	115	249	1902	Well above average
East Taratahi	102	201	1973	Highest
Wellington Airport	125	205	1960	Well above average
Haast	512	252	1986	Highest
Tara Hills, Omarama	110	235	1950	Well above average

Sunny in the north and east of the North Island, and the south of the South Island, less sunshine than normal in the southwest of the North Island

Sunshine totals were at least 110 percent of normal in Auckland, Bay of Plenty, Gisborne, Hawke’s Bay and Southland. Sunshine was below normal in Taranaki, Manawatu, and Wellington.

High January sunshine was recorded at:

Location	January sunshine (hours)	Percentage of normal	Year Records began	Comments
Invercargill Airport	215	119	1932	Well above average

Low January sunshine was recorded at:

Location	January sunshine (hours)	Percentage of normal	Year Records began	Comments
New Plymouth Airport	207	85	1973	3rd equal lowest

January climate in the four main centres

Of the four main centres, Christchurch was the driest, and Auckland the sunniest and warmest. It was wet in Wellington and Auckland, and below average rainfall occurred in the other two centres. Temperatures were well above normal in all four centres. Sunshine hours were below normal in Wellington, and near normal in Auckland, Christchurch, and Dunedin.

	Auckland a	Wellington	Christchurch c	Dunedin
Jan. mean temp. (°C)	20.5 a	17.5	18.8	16.3
Dep. from normal (°C)	+0.9	+0.6	+1.4	+1.1
	Above average	Above average	Above average	Above average
Jan. rainfall (mm)	110 b	112	26	40
% of normal	147	155	62	55
	Above average	Above average	Below average	Well below average
Jan. sunshine (hours)	238 a	205	218	179
% of normal	103	83	95	101
	Near average	Below average	Near average	Near average

^a Mangere    ^b Mt Albert   ^c Christchurch Airport

Highlights and extreme events

• The highest January 2004 temperature was 38.4°C, recorded at Darfield on the 1^st; equal to the highest January temperature on record for the South Island, and second only to 38.9°C recorded in Ruatoria in the North Island on 11 January 1979. This and other high temperatures in January 2004 included:

  Location	Daily maximum temperature (°C)	Date of occurrence	Records began	Comments
  Darfield	38.4	1 Jan.	1939	Highest for January
  Woodbury	37.0	1 Jan.	1994	Highest for January
  Timaru Airport	36.1	1 Jan.	1962	Highest for January
  Winchmore	35.8	1 Jan.	1950	2nd highest for January
  Hororata	36.0	1-2 Jan.	1962	Highest for January
  Culverden	35.0	1-2 Jan.	1984	Highest for January
  Snowden	34.7	3 Jan.	2000	Highest for January
  Middlemarch	35.0	3 Jan.	2001	Highest for January
  Kerikeri EWS	30.3	9 Jan.	1982	Highest for any month
  Whangarei Airport	31.0	9 Jan.	1968	Highest for any month
  Whitianga Airport	30.3	12 Jan.	1991	Highest for January
  Waione	33.5	3 Jan.	1992	Highest for any month
  Castlepoint	32.2	3 Jan.	1973	Highest for any month
  East Taratahi	34.2	3 Jan.	1973	Highest for January

• The lowest temperature for the month was –0.2°C, recorded at Manapouri Airport on the 21^st.
• A depression brought significant rainfall to the lower North Island from the 18^th-23^rd, with heavy falls, totalling 50 to 100 mm in Wairarapa on the 20^th. The same weather system produced high winds in Hawke’s Bay (gusts to 109 km/h at Napier Airport on the 20th) and severe southerly gales through Cook Strait (with gusts to 174 km/h at Baring Head and 146 km/h at Brothers Island on the 21st). The severe gales and high seas resulted in the cancellation of fast-ferry sailings for two days.
• High rainfall totalling 150 to 200 mm occurred in parts of Northland, especially Kaitaia, from the 29-30^th. Rainfall totalling 74 mm was measured at St Bathans (Otago) and the 30^th, with reports of flash flooding in the Wanaka.

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.