Saturday, 1 February 2003
Above average rainfall in the north of the North Island, but dry elsewhere Significant soil moisture deficits now in Manawatu, Horowhenua, Gisborne and Hawke’s Bay Cool
January was a dry month for much of the country. Rainfall was less than half of normal in the southwest of the North Island and Hawke’s Bay, and about a quarter in the Horowhenua. Only half normal rainfall also occurred in central Marlborough. As a consequence significant soil moisture deficits have developed in Gisborne, Hawke’s Bay, the Manawatu and Horowhenua, and remain in Marlborough but have eased slightly in Canterbury and Otago.
In contrast it was wet in the north of the North Island with double average rainfall in eastern Northland and Coromandel. Temperatures were generally below average, with departures of 1°C or more in the King Country and parts of Central Otago. The national average temperature was 16.4°C, 0.6°C below normal.
Sunshine totals were above average in the west of the South Island and Canterbury, and also in the southwest of the North Island. Parts of Northland and Bay of Plenty received less sunshine than normal.
More anticyclones (‘highs’) between Tasmania and the South Island were responsible for these patterns, producing lighter south-westerly quarter winds onto the South Island and easterly quarter winds over northern New Zealand.
Below average rainfall in many areas
Rainfall totals were only about a quarter in the Horowhenua, and half of average elsewhere in the southwest of the North Island, Hawke’s Bay, and parts of Marlborough. About three quarters of the normal totals fell for much of the remainder of the South Island, Gisborne and Wairarapa.
Low January rainfall was recorded at:
| Location | January rainfall (mm) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Normanby | 28 | 33 | 1986 | 3rd lowest |
| Palmerston North | 21 | 33 | 1928 | 3rd lowest |
| Whakatu | 9 | 30 | 1983 | Lowest |
Above average rainfall in the north of the North Island
Rainfall totals were at least 150 percent of average in Northland, Auckland, Coromandel, and western Bay of Plenty, and double average in eastern parts of Northland and Coromandel.
Near or record high January rainfall was recorded at:
| Location | January rainfall (mm) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Kerikeri | 217 | 147 | 1982 | 3rd highest |
| Kerikeri Airport | 215 | 185 | 1979 | 3rd highest |
| Whitianga Airport | 237 | 213 | 1991 | Highest |
| Paeroa | 204 | 250 | 1914 | 3rd highest |
Cool in most places
It was a cool month with below average temperatures in many areas. The national average temperature of 16.4°C was 0.6°C less than the 1961–90 normal. Temperatures were over 1°C below normal in the King Country and eastern parts Otago, and around 0.5°C below average in many other areas. Only in the west and south of the South Island were temperatures near normal.
Above average sunshine in parts of the South Island
Sunshine and solar radiation totals were above average in the west of the South Island, Marlborough, Canterbury and the southwest of the North Island. These were below average in Northland, and the Bay of Plenty. In other areas near average totals occurred.
Highlights
Extreme temperatures
- The highest air temperature for the month was 34.0°C, recorded at Darfield on the 3 January. The highest January air temperature on record there is 36.3°C.
- The lowest air temperature for the month was –3.0°C, recorded at The Chateau, Mt Ruapehu on 15 January. The lowest January air temperature on record there is –7.7°C.
High rainfall
- High rainfall, totalling 100 to 200 mm, was recorded throughout eastern Northland, Coromandel, Waikato, and Bay of Plenty between the 4th and 10th. The wettest days were the 8th and 9th, when many locations recorded between 60 and 120 mm. The rainfall was also accompanied by wind, and resulted in surface flooding in these regions, especially on the Coromandel, creating washouts in holiday parks, disrupting the plans of many campers.
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.