Sunday 16 December 2001
A spring of extremes 5th warmest spring overall Extremely wet in eastern Bay Of Plenty, Marlborough and Nelson
The spring of 2001 was one of the warmest on record, being the fifth warmest since reliable measurements began in the 1850s. It was a season of extremes, beginning with rather settled weather in September. However, unsettled conditions prevailed in many regions in both October and November, especially in central New Zealand, resulting in the wettest spring on record in parts of Marlborough and Nelson.
The national average temperature of 12.9°C was 0.8°C above the normal (1961–1990) spring temperature. Mean temperatures were 1.0°C or more above normal in many northern and western regions from Northland to Fiordland, as well as Nelson, Southern Lakes and Southland.
It was also very wet in eastern Bay of Plenty, and rainfall was above average in many coastal areas of the North Island. Contrasting drier than normal conditions occurred throughout the central North Island volcanic plateau and the Southern Lakes district of the South Island. The transition from drought to deluge in central New Zealand alleviated severe early spring soil moisture deficits in the north of the South Island, although high soil moisture deficits are still present in parts of inland Otago and South Canterbury.
Buller and Southland experienced above average sunshine hours, while less sunshine than usual prevailed in Bay of Plenty, Wellington, Marlborough and Canterbury.
Spring began with more frequent anticyclones (‘highs’) over central New Zealand in September. A marked change occurred after that, with the October and November climate patterns dominated by more frequent depressions (‘lows’) than average in the mid Tasman Sea, extending troughs of low pressure over northern and central New Zealand. Overall, these patterns acted to reduce the frequency of the normal spring westerly winds and resulted in more frequent northeasterlies over much of the country.
Extremely warm in the north, west, and south
Mean temperatures were 1.0°C or more above normal throughout much of Northland, Auckland, western regions from Waikato to Fiordland, as well as Nelson, Southern Lakes and Southland, and at least 0.5°C above normal in most other regions. Temperatures were near average in coastal Wairarapa.
Near or record high mean spring temperatures were recorded at:
| Location | Mean temperature (°C) | Departure from normal | Year records began | Comments |
|---|---|---|---|---|
| Kaitaia Observatory | 15.6 | +1.1 | 1985 | Highest |
| Dargaville | 15.6 | +1.7 | 1943 | 2nd highest |
| Whangarei Airport | 15.8 | +1.3 | 1967 | 2nd highest |
| Auckland, Owairaka | 15.3 | +1.2 | 1949 | Highest |
| Auckland Airport | 15.4 | +1.0 | 1962 | 3rd highest |
| Pukekohe | 15.0 | +1.3 | 1970 | Highest |
| Hamilton Airport | 14.2 | +1.3 | 1970 | Equal highest |
| New Plymouth Airport | 13.8 | +1.1 | 1944 | 2nd highest |
| Ohakune | 11.6 | +1.3 | 1962 | Highest |
| Wanganui | 14.3 | +1.0 | 1937 | 3rd equal highest |
| Palmerston North Airport | 13.3 | +1.0 | 1962 | Equal highest |
| Wellington Airport | 13.9 | +1.1 | 1962 | 3rd equal highest |
| Farewell Spit | 14.2 | +1.5 | 1971 | Equal highest |
| Westport Airport | 13.1 | +1.3 | 1937 | 3rd highest |
| Hokitika Airport | 12.4 | +1.2 | 1964 | 3rd highest |
| Milford Sound | 11.4 | +1.2 | 1935 | 3rd equal highest |
| Puysegur Point | 11.4 | +1.2 | 1981 | Highest |
| Nelson Airport | 13.4 | +1.3 | 1943 | 2nd highest |
| Queenstown | 12.1 | +1.5 | 1871 | Highest |
| Queenstown Airport | 10.9 | +1.2 | 1968 | Highest |
| Lauder | 11.3 | +1.2 | 1981 | 2nd highest |
| Invercargill Airport | 10.9 | +1.0 | 1948 | Equal highest |
| Tiwai Point | 11.5 | +1.1 | 1970 | Highest |
| Raoul Island | 18.8 | +1.2 | 1940 | 2nd equal highest |
Unusually wet in eastern Bay Of Plenty, Marlborough and Nelson
Rainfall was at least 150 percent of normal in eastern Bay of Plenty, Marlborough and Nelson, and at least 110 percent of normal in Northland, Coromandel, Gisborne, Taranaki, Wanganui, Wellington, and many other coastal areas of the North Island.
Near or record high spring rainfall was recorded at:
| Location | Spring rainfall (mm) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Whakatane Airport | 435 | 156 | 1976 | 2nd highest |
| Whakatane | 477 | 197 | 1947 | 3rd highest |
| Nelson Airport | 385 | 152 | 1941 | Highest |
| Blenheim | 297 | 194 | 1930 | Highest |
| Blenheim Airport | 315 | 177 | 1941 | Highest |
Below average rainfall in the central North Island and southern lakes
Rainfall was less than 75 percent of normal in the central North Island volcanic plateau and the Southern Lakes district of the South Island, as well as isolated areas in southern Hawke’s Bay, and parts of south Canterbury.
Near record low spring rainfall was recorded at:
| Location | Spring rainfall (mm) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Ohakune | 259 | 67 | 1961 | 3rd lowest |
Sunny in Buller and Southland Cloudy in Bay Of Plenty, Wellington, and many eastern areas
Sunshine and solar radiation totals were above average in Buller and Southland, and below average in Bay of Plenty, Wellington, Marlborough and Canterbury. Most other regions experienced near average sunshine hours.
Highlights
Extreme temperatures
- The highest air temperature for the spring was 30.1°C, recorded at Darfield, on 30 November.
- The lowest air temperatures for the spring was -5.5°C, recorded twice at Waiouru on 25 September and 25 October, and also at The Chateau, Mt Ruapehu on 25 October.
Significant rainfall and flooding
- Heavy rainfall, with surface flooding occurred throughout Northland on 5 October, with rain as high as 25 mm in an hour, and temporary closure of a number of roads. Many sites in the region measured rainfall totalling between 75 and 100 mm in the 24 hours to 9 am on that same day. Heavy rainfall and surface flooding also occurred in the Auckland region.
- High rainfalls resulted on 22 November, with totals from 50 to 100 mm throughout the Wellington-Hutt Valley region (where slips and surface flooding resulted, causing a few road closures and traffic delays). Water was knee-high on a Newlands Road. Much of the Wellington rainfall occurred within six hours.
Tornadoes
- High winds occurred with the passage of a 100-metre-wide waterspout/tornado through Cable Bay, Northland, at about 12.30 pm on 9 October, 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.
- Four tornadoes were sighted on 4 November at Awakeri, near Whakatane, one totally destroyed a hay-barn on a farm, just missing nearby residents.
High winds and rough weather
- 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.
- High winds and heavy rainfall buffeted the Gisborne region over the night of 22 October, resulting in extensive damage in kiwifruit orchards.
- Storm-force southerlies buffeted Cook Strait, with wind gusts to 198 km/h at Baring Head on 17 November.
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.