Tuesday, 1 April 2003
Exceptionally dry in Wanganui, Manawatu, Wairarapa, and Otago End of month rainfall brings relief to areas in extreme soil moisture deficit in Canterbury, but Wanganui, Manawatu, Horowhenua, Marlborough and Otago still in significant deficit Record high rainfall in parts of Northland The warmest month of the year with record high mean temperatures in inland Otago The sunniest March ever in Kapiti, Wellington, and Dunedin, and extremely sunny over the rest of central and southern parts
For much of New Zealand, March was a month of new records produced by very settled, extremely dry and unusually sunny weather patterns, except in the north. Significant rainfall brought relief to many drought-affected areas at the end of the month.
Very little rainfall occurred, at many locations in the south and west of the North Island, from Wanganui to Wellington, and throughout much of Nelson, Marlborough, Canterbury and Otago until after 27 March. Until then most stations in these regions recorded totals of 10 mm or less. Christchurch Airport and Lauder, had no measurable rainfall in this period. Parts of Manawatu, Horowhenua, and Kapiti had not had a day’s rainfall exceeding 10 mm since Christmas or before. Substantial rainfall, totalling 50–90mm, occurred throughout north Canterbury from the 28th to the 30th.
For the month, rainfall was less than 25 percent (quarter) of average in Central Otago, and less than 50 percent (half) of average at most locations in the southern half of the North Island, and over much of the South Island. Rainfall was near average in Waikato, and in much of Bay of Plenty. In contrast, rainfall was more than twice (200 percent) average in parts of Northland, and above average in Auckland, Coromandel, and areas of Gisborne, due to significant amounts that occurred during the second and last week of the month. Rainfall was also above average in north Canterbury.
Significant soil moisture deficits continued throughout the north and east of the South Island, from Nelson to Otago, as well as the southwest North Island from Wanganui to Wellington, and Wairarapa. The end-of-month rainfall resulted in major relief for Nelson and north Canterbury soils.
Mean temperatures were above average in the west of the North Island from Auckland to Wellington, and over much of the South Island, but it was very much warmer than usual, with mean temperatures at least 1.5°C above average in the Southern Lakes district and Central Otago. The national average temperature of 16.7°C was 0.8°C above normal, making March 2003 the warmest month this year and warmer than the usual months of summer.
Extremely high sunshine and solar radiation totals were recorded at many locations throughout the south and west of the North Island and in the South Island. Sunshine hours were below average in Northland, Auckland, and Gisborne.
While anticyclones (‘highs’) dominated New Zealand’s March climate pattern, they were more frequent than average to the south and east of the South Island. Below average pressures prevailed between Northland and New Caledonia. This pattern produced more frequent airflow from the northeast than is usual over New Zealand.
Well below average rainfall in the Southern North Island and over much of the South Island Above average rainfall in the north of the North Island
Rainfall totals were less than 50 percent (half) of average at most locations in the southern half of the North Island, and over much of the South Island (apart from Nelson and Canterbury). Rainfall was less than 25 percent (quarter) of average in Central Otago.
Contrasting totals, at least 200 percent of average, occurred in parts of Northland, with at least 125 percent of average rainfall in Auckland, Coromandel, areas of Gisborne, and in north Canterbury. Totals were near average in Waikato, much of Bay of Plenty, and much of Canterbury.
Rather low March rainfall was recorded at:
| Location | March rainfall (mm) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| East Taratahi | 16 | 33 | 1973 | Lowest |
| Haast | 106 | 29 | 1941 | 3rd lowest |
| Tara Hills | 10 | 19 | 1949 | 3rd equal lowest |
| Middlemarch | 6 | 11 | 1907 | Well below average |
| Dunedin Airport | 12 | 19 | 1963 | 3rd lowest |
| Queenstown Airport | 16 | 23 | 1969 | Lowest |
| Lauder | 8 | 12 | 1943 | Well below average |
| Clyde | 9 | 21 | 1983 | Lowest |
| Invercargill Airport | 33 | 35 | 1940 | 3rd lowest |
| Tiwai Point | 38 | 41 | 1971 | 3rd lowest |
| Nugget Point | 20 | 24 | 1930 | 3rd lowest |
High March rainfall was recorded at:
| Location | March rainfall (mm) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Kaitaia Observatory | 226 | 263 | 1986 | Highest |
| Kerikeri EWS | 335 | 204 | 1982 | 2nd highest |
| Kerikeri Airport | 395 | 237 | 1978 | 2nd highest |
| Kaikohe | 245 | 186 | 1973 | Highest |
| Whangarei Airport | 248 | 189 | 1937 | Well above average |
| Auckland, Owairaka | 196 | 207 | 1949 | Well above average |
Extremely sunny over much of the South Island and Southwestern North Island
Sunshine and solar radiation totals were well above average (at least 120 percent of normal) throughout the south and west of the North Island, and almost all of the South Island, with near or record high totals recorded at many locations in these regions. Sunshine hours were less than 90 percent of average in Northland, Auckland, and Gisborne.
Near or record high March sunshine hours were recorded at:
| Location | March sunshine (hours) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Paraparaumu Airport | 280 | 150 | 1953 | Highest |
| Wellington, Kelburn | 267 | 144 | 1928 | Highest |
| Arapito | 226 to 29th | 148 | 1980 | Highest |
| Hokitika Airport | 235 | 145 | 1964 | 2nd highest |
| Nelson Airport | 273 | 135 | 1949 | 2nd highest |
| Dunedin, Musselburgh | 203* | 153 | 1948 | Highest |
| Invercargill Airport | 178 | 135 | 1932 | 2nd equal highest |
* Missing a day
Near or record high March solar radiation was recorded at:
| Location | March solar radiation (MJ/m2) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Palmerston North Airport | 17.7 | 120 | 1992 | Highest |
| Levin | 18.0 | 122 | 1972 | Highest |
| Wanganui, Spriggens Park | 18.1 | 116 | 1997 | Highest |
| Hokitika Airport | 16.2 | 118 | 1969 | 3rd equal highest |
| Nelson Airport | 18.7 | 120 | 1969 | 3rd highest |
Average or above average temperatures in most regions
Mean temperatures were at least 0.5°C above average in the west of the North Island from Auckland to Wellington, including Wairarapa, and over much of the South Island. It was very much warmer than usual, with mean temperatures at least 1.5°C above average in the Southern Lakes district and Central Otago. Temperatures were near average in Northland, Coromandel, Bay of Plenty, Gisborne, Hawke’s Bay, Buller, Westland, and Marlborough.
Near or record high mean March temperatures were recorded at:
| Location | Mean temperature | Departure (°C) | Records began | Comments |
|---|---|---|---|---|
| Palmerston North Airport | 18.3 | +1.9 | 1962 | 3rd equal highest |
| Farewell Spit | 18.4 | +1.7 | 1977 | Highest |
| Wanaka Airport | 16.1 | +2.2 | 1993 | Highest |
| Queenstown | 16.8 | +2.4 | 1872 | Highest |
| Queenstown Airport | 14.8 | +1.5 | 1969 | 2ndequal highest |
| Lauder | 15.4 | +2.4 | 1982 | Highest |
| Clyde | 16.3 | +2.0 | 1983 | Highest |
Afternoon maxima were very much higher than average in the southwest of the North Island from Manawatu to Kapiti, including parts of the central North Island Volcanic Plateau and Wairarapa, inland south Canterbury, and Otago.
Near or record high mean daily maximum March temperatures were recorded at:
| Location | Mean daily maximum temperature | Departure (°C) | Records began | Comments |
|---|---|---|---|---|
| Turangi | 22.5 | +1.5 | 1968 | 3rd highest |
| East Taratahi | 24.1 | +2.5 | 1973 | 2nd equal highest |
| Paraparaumu Airport | 22.2 | +1.9 | 1953 | 2nd highest |
| Palmerston North Airport | 24.5 | +3.0 | 1962 | 2nd highest |
| Levin | 23.8 | +3.1 | 1896 | Equal highest |
| Hanmer Forest | 23.7 | +3.0 | 1906 | 2nd highest |
| Tara Hills | 22.5 | +2.5 | 1950 | Highest |
| Wanaka Airport | 23.2 | +2.4 | 1993 | Highest |
| Manapouri airport | 19.9 | +1.9 | 1991 | 2nd highest |
| Queenstown | 23.4 | +3.6 | 1872 | Highest |
| Queenstown Airport | 21.0 | +2.1 | 1969 | Highest |
| Lauder | 22.8 | +3.0 | 1982 | Highest |
| Clyde | 23.4 | +2.8 | 1983 | Highest |
| Ettrick | 22.4 | +2.3 | 1985 | 2nd highest |
Highlights
Extreme temperatures
- The highest air temperature for the month was 31.8°C, recorded at Hanmer Forest on the 21st. The highest March air temperature on record there is 32.4°C.
- Heat-wave like conditions occurred in the southwest North Island on the 2nd, Levin recording 31.0°C, a new record high temperature extreme for any time of the year there in records going back to 1896.
- The lowest air temperature for the month was –1.0°C, recorded at both Manapouri Airport and Lumsden on the 18th. The lowest March air temperatures on record at Manapouri Airport and Lumsden are –5.5°C and –2.9°C respectively.
Heavy rainfall
- Heavy rainfall occurred in the Bay of Islands, parts of Auckland, Coromandel, and areas of Gisborne during the second week of the month, and in Northland during the last week. Rainfall totals recorded for these events:
Location Rainfall total (mm) Date of occurrence Kerikeri Airport 178.0 9–10 March Owairaka, Auckland 129.4 10–11 March Whitianga Airport 108.4 10–11 March Gisborne Airport 83.2 11–12 March Kaitaia EWS 151.0 27 March Kerikeri Airport 116.4 27 March Kaikohe 126.0 27 March - Surface flooding occurred in parts of Northland and Auckland on the 27th and 28th, being widespread in Kaitaia.
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.