Wednesday, 1 May 2002
Drier in western regions, above average rainfall in parts of Bay of Plenty and the eastern South Island Warm and sunny in the west of the South Island, average or below average temperatures and sunshine elsewhere
April brought large contrasts between western and eastern areas of New Zealand. Below average rainfall with above normal temperatures and abundant sunshine occurred in the west, particularly on the South Island West Coast. Above average rainfall and below average sunshine featured in the east of the South Island. Temperatures were lower than normal in the east of the North Island. Cold southerlies and southeasterlies at the start of April resulted in early snowfall to high country areas, while huge swells resulted in damage to roads and property in some eastern coastal regions.
Rainfall was below normal in most western regions, and also in eastern Northland, Coromandel, Gisborne, northern Hawke’s Bay and Wairarapa. It was very dry, with rainfall 50 percent (half) or less than normal in south Taranaki, Horowhenua, Wellington, central Marlborough, Buller, north Westland and Fiordland. Significant soil moisture deficits for the time of year still exist in central Otago and inland south Canterbury. Above average rainfall occurred in inland and eastern Bay of Plenty, Tongariro, Canterbury, and Otago, due to a few days with high rainfall in these regions toward the end of the month.
Temperatures were above average on the West Coast, and in coastal Southland. However, they were below average in Marlborough and the east and southwest of the North Island. The national average mean temperature of 13.2°C was close to the April normal of 13.3°C.
Buller, Westland and western Bay of Plenty, experienced more sunshine than normal. Sunshine totals were lower than average in the east from Wellington to Southland.
April’s climate pattern was dominated by many more anticyclones (‘highs’) than usual over the South Tasman Sea and the southern half of the South Island. South easterlies were more frequent than normal over the country, producing more onshore winds than usual in all eastern regions.
Below average rainfall in western regions
Rainfall was less than 75 percent of normal in western regions of New Zealand from Auckland to Fiordland, and also in eastern Northland, Coromandel, Gisborne, northern Hawke’s Bay, Wairarapa and central Marlborough. Totals were 50 percent or less than normal in south Taranaki, Horowhenua, Wellington, parts of central Marlborough, Buller, north Westland and Fiordland.
Near or record low April rainfall was recorded at:
| Location | April rainfall (mm) | Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Matamata | 31 | 31 | 1966 | 3rd lowest |
Above average rainfall in parts of Bay of Plenty and the Eastern South Island
Rainfall was at least 120 percent of average in inland and eastern Bay of Plenty and Tongariro, due to high rainfall in these regions from the 24th to the 26th.
Rainfall was also at least 120 percent of average in Canterbury and Otago, due to substantial rainfall from the 27th to the 28th.
Warm in the west of the South Island, average or below average temperatures elsewhere
Mean temperatures were about 0.5°C above normal on the West Coast, and in coastal Southland. However, they were 0.5 to 1.0°C below normal in Marlborough, the east of the North Island from east Cape to Wairarapa, Manawatu and Horowhenua. In Canterbury, mean daily maximum temperatures were 1.0 to 1.5°C below normal, while mean daily minimum temperatures were 1.0 to 1.5°C above normal.
Sunny on the west coast, cloudy in the east from Wellington to Southland
Sunshine and solar radiation totals were at least 110 percent of average in Buller, Westland and western Bay of Plenty. Lower than normal sunshine occurred in the east from Wellington to Southland.
Highlights
Extreme temperatures
- The highest air temperature for the month was 26.3°C, recorded at Middlemarch on the 26th. The highest April air temperature on record in the Middlemarch area is 29.4°C.
- The lowest air temperature for the month was –4.0°C, recorded at Lake Rotoiti on the 3rd. The lowest April air temperature on record at Lake Rotoiti is –6.5°C.
Cold southerlies and early snowfall
- Cold southerlies on 2 April produced snowfall on Mt Taranaki, to its lowest level on record for the time of year. Snow also lay on the Desert Road, and in hill country areas on Banks Peninsula.
Strong winds and huge seas batter coasts
- Huge seas, generated by strong southeasterlies, battered eastern coastlines of both islands on the 3rd and 4th. Powerful waves smashed through walls of beachfront baches in Hawke’s Bay between Haumoana and Te Awanga south of Napier. Wellington’s southern coast road was closed by debris. Most Cook Strait ferry sailings were cancelled, affecting more than 2000 travellers. A 12-km stretch of SH1 south of Kaikoura was badly damaged and closed for 12 hours.
- Further high seas (with 5.5 to 9-metre waves) occurred with gale force southerlies through Cook Strait on the 29th, resulting in the 8am fast-ferry from Wellington having to turn back and cancellations of other fast-ferry sailings for the day. The Inter-island Ferry took 6 hours to cross.
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.