October 2001

Thursday 1 November 2001
One of the warmest octobers on record
Below average rainfall in the southwest of the South Island
Well above average rainfall in Nelson, Marlborough and several North Island regions
Rather cloudy in Canterbury and the south and west of the North Island
New Zealand had the 3rd warmest October on record since reliable measurements began in the 1850s, half the normal rainfall in the Southern Lakes, and double the usual rainfall in areas of the North Island, Nelson, and Blenheim.

Thursday 1 November 2001

One of the warmest octobers on record Below average rainfall in the southwest of the South Island Well above average rainfall in Nelson, Marlborough and several North Island regions Rather cloudy in Canterbury and the south and west of the North Island

New Zealand had the 3rd warmest October on record since reliable measurements began in the 1850s, half the normal rainfall in the Southern Lakes, and double the usual rainfall in areas of the North Island, Nelson, and Blenheim. But soil moisture deficits remained very high for the time of year in inland areas of both Otago and south Canterbury./p>

The national average temperature of 13.4°C was 1.3°C above the mean October temperature during 1961-1990. The only other warmer Octobers were those of 1961 (13.8°C) and 1893 (13.7°C). Mean temperatures were much higher than usual in many North Island regions, as well as Nelson, and the South Island West Coast, being at least 1.5°C above normal. Onshore north-easterlies kept mean temperatures close to average in north Canterbury, and up to 1°C below average along the Kaikoura coast.

Rainfall was below normal in the Southern Lakes, south Westland, Fiordland, and much of Southland. In contrast, more than double the normal rainfall occurred in parts of Northland, Taranaki, eastern Bay of Plenty, the east of the North Island from Gisborne to Wairarapa, as well as Nelson and Blenheim. It was also wet in Auckland, Coromandel, Wanganui, Manawatu, Wellington, Golden Bay, and east coast areas of the South Island from Kaikoura to Otago.

The month was very cloudy in Canterbury and the south and west of the North Island. Most other regions had near average or slightly below average sunshine hours.

The October climate pattern was one with more frequent depressions (‘lows’) than average in the eastern Tasman Sea and over the North Island. Pressures were above average to the south of the Chatham Islands. These acted to reduce the normal spring westerly winds and produced more frequent northerlies over northern New Zealand, and north-easterlies and easterlies over the remainder of the country.

Very warm in many regions

Mean temperatures were very much higher than normal in Northland, Auckland, Waikato, Wanganui, Manawatu, Nelson, and the South Island West Coast, with mean temperatures at least 1.5°C above normal. It was also warmer than average in most other North Island regions, along with central Marlborough, mid Canterbury, and western Southland, with mean temperatures about 1°C above normal. More frequent north-easterlies kept mean temperatures up to 0.5°C above average in coastal southern Hawke’s Bay and north Canterbury, and as much as 1°C below average along the Kaikoura coast.

Near or record high mean October temperatures were recorded at:

Location Mean temperature October (°C) Departure from normal (°C) Year Records began Comments
Kaitaia Observatory 15.8 +1.6 1985 Highest
Kerikeri 15.9 +1.7 1981 Highest
Whangarei Airport 16.5 +2.1 1967 Highest
Warkworth 15.3 +1.7 1972 2nd highest
Auckland, Owairaka 16.2 +2.1 1949 Highest
Auckland 16.2 +1.9 1868 Highest
Pukekohe 16.0 +2.6 1970 Highest
Paeroa 15.6 +1.7 1947 Equal highest
Tauranga Airport 15.5 +1.8 1913 Highest
Hamilton, Ruakura 15.1 +2.0 1907 Highest
Hamilton Airport 14.9 +2.1 1970 Highest
Turangi 13.3 +2.0 1968 Highest
Gisborne Airport 15.6 +1.8 1905 3rd highest
Palmerston North Airport 14.0 +1.9 1962 Highest
Wallaceville 13.7 +1.9 1940 Equal highest
Farewell Spit 14.7 +2.1 1971 Highest
Westport Airport 13.9 +2.1 1937 Highest
Arapito 13.9 +1.9 1979 Equal highest
Hokitika Airport 13.1 +2.1 1866 Highest
Milford Sound 11.8 +1.7 1935 Highest
Nelson Airport 14.2 +2.0 1943 Highest
Queenstown Airport 11.3 +1.7 1968 2nd highest

Well below average rainfall in teh southern lakes catchments

Rainfall was about half of the normal amounts in the Southern Lakes, and less than three quarters of normal in south Westland, Fiordland, and much of Southland.

Well above average rainfall in Nelson, Marlborough and many North Island regions

Rainfall was more than double normal in parts of Northland, Taranaki, eastern Bay of Plenty, the east of the North Island from Gisborne to Wairarapa, Nelson, and Blenheim. Rainfall was also above average in Auckland, Coromandel, Wanganui, Manawatu, Wellington, Golden Bay, and east coast areas of the South Island from Kaikoura to Otago, where many locations recorded more than 120 percent of normal October values. Near or record high October rainfall was recorded at:

Location October Rainfall (mm) Percentage of normal Year Records began Comments
Te Paki, Far North 201 275 1931 Highest
Kaitaia Observatory 201 200 1985 Highest
Whakatane Airport 221 220 1975 2nd highest
Whakatane 219 284 1992 Highest
Palmerston North Airport 137 190 1943 2nd highest
Normanby 203 230 1977 2nd highest
Appleby 219 243 1932 2nd highest
Nelson Airport 286 321 1941 Highest
Blenheim Airport 178 278 1941 Highest
Blenheim Research 161 286 1930 Highest

The record high Nelson rainfall was due to three high rainfall events on the 6th, the 8th, the 19th of October.

Rather cloudy in Canterbury and the south and west of the North Island

Sunshine and solar radiation totals were well below average in Canterbury and the south and west of the North Island from Taranaki to Wellington. Sunshine hours were near or slightly below average elsewhere. Very low October sunshine totals were recorded at:

Location October sunshine (hours) Percentage of normal Year Records began Comments
New Plymouth Airport 149 79 1973 Lowest
Paraparaumu Airport 131 73 1953 3rd lowest
Wellington, Kelburn 125 64 1928 2nd lowest
Christchurch Airport 143 70 1949 Equal lowest

Highlights

Extreme temperatures

  • The highest air temperature for the month was 29.4°C, recorded at Darfield on the 2nd. The highest October air temperature on record at Darfield is 30.0°C. A record high October air temperature (26.0°C) was measured at Henderson, west Auckland on the 31st, where measurements commenced in 1986.
  • The lowest air temperature for the month was –5.5°C, recorded at both Waiouru and The Chateau, Mt. Ruapehu on the 25th. This was a new October record for Waiouru, where measurements began in 1966. The lowest October air temperature on record for The Chateau, Mt. Ruapehu is –8.3°C.

High rainfall

  • Heavy rainfall at Whakatane totalled 101 mm for the 24 hours to 9am on the 10th.

Tornadoes in the far North

  • High winds occurred with the passage of a 100-metre wide waterspout/tornado through Cable Bay, Northland, at about 12.30 p.m. on the 9th, resulting in damage to about 19 houses, some extensive. Another tornado was report on the same day, at Mata, 22 km southeast of Whangarei, moving a barn 100 metres across a paddock.

Rough weather in Gisborne

  • High winds and heavy rainfall buffeted the Gisborne region over the night of the 22nd, resulting in extensive damage in kiwifruit orchards.

Stormy conditions affect the North Island

  • Squally north-westerlies with isolated thunderstorms and heavy rainfall affected many northern and western North Island regions, with the approach of an active cold front, during the night of 31 October. Parts of Auckland appeared to be worst affected with fallen trees, and at least 10 houses having damaged roofs, associated with the passage of a ‘vortex’ and wind gusts to about 150 km/h. Fallen trees were also reported in Tauranga and Rotorua.

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.