Sunday, 2 March 2003
Below average rainfall in Nelson, and many North Island areas Significant soil moisture deficits affects many regions High end-of-month rainfall in eastern Northland, Coromandel and parts of Gisborne – floods at Paeroa Extremely sunny in the east Below average temperatures persist in most regions Unseasonably early frosts
Waikato, Taranaki, and Nelson all received less than a quarter (25 percent) of their normal February rainfall last month, while less than half (50 percent) of average rain fell in northwestern parts of Northland, and most central and southwestern areas in the North Island. Totals were less than 75 percent of average in southern Wairararapa, north Canterbury, and west Otago. Significant soil moisture deficits affected a substantial proportion of the country. Overall, February was also cooler but sunnier than average. Unseasonably early frosts, extreme in some areas for February, occurred in inland and eastern regions between the 20th and 23rd, and heavy rainfall occurred in some northern and eastern North Island regions toward the end of the month, with flooding in Paeroa.
In Hawke’s Bay, some farms carted in water, bought extra feed or used supplements. For much of the month, the dry conditions resulted in total fire bans in Gisborne, Hawke’s Bay, and Bay of Plenty, with restrictions applied in most other areas of New Zealand. Inadequate rainfall meant that significant soil moisture deficits persisted in most eastern regions from Gisborne to Central Otago, as well as in Nelson, Waikato, Bay of Plenty, Taranaki, Wanganui, Manawatu, and Horowhenua, and affected most other North Island regions for most of the month.
High rainfall occurred in some northern and eastern North Island regions toward the end of the month. However, in eastern Northland, and Coromandel, it was extremely dry in February until substantial heavy rainfall occurred from the 25th, some locations recording less than 10 mm up until then. Their high end-of-month rainfall (over 150 mm in places) resulted in above average February rainfall in these regions. Rainfall was near average over much of the South Island, but parts of coastal Otago and the Arthur’s Pass district were wetter than average.
It was another relatively cool month over much of New Zealand, with below average temperatures in many areas, especially at night and in the South Island. Mean temperatures were at least 1.0°C below average on the West Coast, in Southern Lakes, south Canterbury, and western Southland, and more than 2.0°C below average in parts of Fiordland. The national average temperature was 16.4°C, 0.7°C below normal.
February was a sunnier than average month over much of New Zealand, with extremely high sunshine and solar radiation totals recorded in many eastern locations, from Hawke’s Bay to Southland.
Anticyclones (‘highs’) were more frequent than average in the Tasman Sea and east of the Chatham Islands. Westerlies were stronger than usual south of New Zealand and easterlies to the north. This pattern produced more frequent onshore winds over New Zealand.
Below average rainfall in Nelson, and many North Island areas
Rainfall totals were less than 50 percent (half) of average at most locations in Nelson and throughout much of the central and southwestern North Island, and less than 25 percent (quarter) of average in Waikato and Taranaki. Rainfall was also less than 50 percent of average in northwestern parts of Northland, as well as inland Bay of Plenty, Taupo, and the Central North Island Volcanic Plateau. Totals were less than 75 percent (three quarters) of average in southern Wairararapa, north Canterbury, and parts of inland Southland, and west Otago.
Very low February rainfall was recorded at:
| Location | February rainfall (mm) | Percentage of normal | Year Records began | Comments |
|---|---|---|---|---|
| Cape Reinga | 8 | 13 | 1920 | Well below average |
| Kaitaia Observatory | 21 | 21 | 1986 | 2nd equal lowest |
| Kawerau | 33 | 27 | 1955 | 2nd equal lowest |
| Taupo Airport | 13 | 17 | 1991 | 3rd lowest |
| Port Taharoa | 20 | 29 | 1985 | 2nd lowest |
| New Plymouth Airport | 15 | 15 | 1944 | 3rd lowest |
| Levin | 14 | 22 | 1896 | 3rd lowest |
| Takaka | 21 | 16 | 1986 | 2nd lowest |
| Motueka, Riwaka | 5 | 6 | 1943 | Well below average |
| Nelson Airport | 5 | 9 | 1941 | 3rd lowest |
| Chatham Island | 17 | 30 | 1951 | 3rd lowest |
Well above average rainfall in Coromandel and Gisborne
Rainfall was above average, due to the substantial falls toward the end of the month, in eastern Northland (at least 125 percent of average), Coromandel, and parts of Gisborne (more than 200 percent of average). Rainfall was also at least 125 percent of average in parts of coastal Otago and the Arthur’s Pass district.
High February rainfall was recorded at:
| Location | February rainfall (mm) | Percentage of normal | Year tecords began | Comments |
|---|---|---|---|---|
| Pareoa AWS | 334 | 389 | 1991 | Highest |
| Hicks Bay AWS | 246 | 333 | 1991 | Highest |
Extremely sunny in the east
Sunshine and solar radiation totals were near average in Northland and Auckland, but at least 110 percent of average over the rest of New Zealand. Near or record high totals (at least 120 percent of average) were recorded in many eastern locations from Hawke’s Bay to Southland.
Record high February sunshine hours were recorded at:
| Location | February sunshine (hours) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| New Plymouth Airport | 252 | 115 | 1973 | 3rd highest |
| Christchurch | 266 | 138 | 1930 | Highest |
| Dunedin, Musselburgh | 219 | 144 | 1948 | Highest |
| Invercargill Airport | 215 | 134 | 1932 | 2nd highest |
Near or record high February solar radiation was recorded at:
| Location | February solar radiation (MJ/m2) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Motu | 19.1 | 110 | 1992 | Highest |
| Napier Airport | 22.1 | 114 | 1992 | Highest |
| Blenheim Airport | 22.7 | 115 | 1992 | Highest |
| Hanmer Forest | 21.4 | 117 | 1996 | Highest |
| Christchurch Airport | 21.8 | 117 | 1960 | 3rd highest |
| Timaru Airport | 20.4 | 118 | 1992 | 2nd Highest |
Below average temperatures persist in most regions
Mean temperatures were at least 0.5°C below average in northern and western areas of both islands, as well as south Canterbury, Otago, and Southland; at least 1.0°C below average on the South Island’s West Coast, Southern Lakes, south Canterbury, and western Southland; and more than 2.0°C below average in parts of Fiordland. Temperatures were near normal in eastern Bay of Plenty, Taupo, Manawatu, the eastern North Island, Marlborough, and north Canterbury.
Near record low mean February temperatures were recorded at:
| Location | Mean temperature | Departure (°C) | Records began | Comments |
|---|---|---|---|---|
| Hokitika Airport | 14.2 | –1.6 | 1964 | Well below average |
| Milford Sound | 12.8 | –2.1 | 1934 | Well below average |
Highlights
Extreme temperatures and frost
- The highest air temperature for the month was 35.5°C, recorded at Darfield on the 8th. The highest February air temperature on record there is 39.4°C. Paraparaumu recorded 29.6°C on the 28th, a new record high temperature extreme for any time of the year in records going back to 1953.
- The lowest air temperature for the month was –2.9°C, recorded at Waiouru on the 22nd. This is the lowest February air temperature on record there. Measurements commenced in 1967. Squash crops were severely damaged by ground frost in parts of Hawke’s Bay, south of Hastings, on the same morning, with as much as 50 percent of the crop lost on some farms.
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Record low February air temperatures were measured at:
Location Minimum air temperature (°C) Date of occurrence Records began Turangi 0.0 22 Feb. 1968 Waiouru –2.9 22 Feb. 1967 Ohakune, Ruapehu College –0.6 22 Feb. 1994 Hastings, Whakatu 2.9 22 Feb. 1983 Masterton, Te Ore Ore 0.5 22 Feb. 1993 Waione 0.2 23 Feb. 1992 Appleby 1.0 22 Feb. 1932 Christchurch Airport 1.5 20 Feb. 1954 Arthur’s Pass –2.0 22 Feb. 1979 -
Record low February grass minimum temperatures were measured at:
Location Grass minimum temperature (°C) Date of occurrence Records began Ohakune, Ruapehu College –3.0 22 Feb. 1994 Hastings, Whakatu –1.2 22 Feb. 1983 Masterton, Te Ore Ore –1.5* 22 Feb. 1993 East Taratahi –2.8 23 Feb. 1973 Wallaceville –3.3 22 Feb. 1940 Christchurch Airport –2.7 20 Feb. 1954 Winchmore –3.6 23 Feb. 1950 Arthur’s Pass –11.0 22 Feb. 1979 Milford Sound –1.0 21 Feb. 1962 * equal lowest
High rainfall
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High rainfall occurred in eastern Northland, Coromandel, and Eastland toward the end of the month, and some houses in Paeroa were evacuated due to flooding on the 27th. Some rainfall totals being:
Location Rainfall total (mm) Date of occurrence Whangarei Airport 65.6 25 Feb. Whitianga Airport 123.4 25–26 Feb. Paeroa 279.8 26–27 Feb. Hicks Bay 191.0 26–27 Feb.
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.