April proved warm to very warm over much of the North Island and the best news was that most drought affected regions received reasonable rainfall totals to either ease or completely break the very dry situation.
Lower air pressures dominated the picture which saw more northwesterly winds than normal affecting the country, resulting in a very warm month for many regions. Northwesterly fronts resulted in extremely heavy rainfall in the western Bay of Plenty on 20 April and in the Nelson and Tasman regions on 21 April.
Some high totals accummulated and more than twice the normal April rainfall total was recorded in the north of the South Island.
Motueka received 267 percent (over two-and-a-half-times) normal April rainfall, with almost half of this occurring in one day, on the 21st (116 mm).
Also, Tauranga received almost two-and-a-half-times its normal rainfall for April (284 mm, 236 percent of normal). Rainfall was also well above normal (above 150 percent of April normal) in parts of Waikato, Bay of Plenty, and Manawatu. Rainfall was above normal (120-150 percent of April normal) in parts of: Northland, Auckland, Kapiti Coast, Canterbury, and coastal Southland.
In contrast, April rainfall was below normal (50 to 80 percent of normal April rainfall) in Central Otago, with some locations recording well below normal rainfall (less than 50 percent of normal April rainfall).
The rainfall during April recharged soils throughout most of New Zealand.
Average temperatures for last month were well above average (more than 1.2°C above the April average) across most of the North Island. Temperatures were above average (between 0.5°C and 1.2°C above the April average) for most of the South Island except for parts of inland Canterbury and Otago.aa
It was the warmest April on record for Leigh, Masterton, Gisborne, Wairoa, and Ohakune. The nationwide average temperature in April 2013 was 14.0°C (0.7°C above the 1971-2010 April average)
The dominance of low pressures during April resulted in a cloudy month for the lower North Island and northern and eastern South Island, with below normal sunshine hours for those areas (75 to 90 percent of normal April sunshine hours).
In contrast, it was a very sunny month for the West Coast of the South Island, south of Franz Josef (more than 125 percent of normal April sunshine). Sunshine was near normal (within 10 percent of normal April sunshine hours) elsewhere. Of the available, regularly reporting sunshine observation sites, the sunniest four centres so far in 2013 (January to April) are New Plymouth (1118 hours), Whakatane (1097 hours), Paraparaumu (1006 hours), and Lake Tekapo (1003 hours).
• The highest temperature was 31.0 °C, recorded at Gisborne on 1 April.
• The lowest temperature was -5.9°C, observed at Ranfurly on 10 April.
• The highest 1-day rainfall was 155 mm, recorded at Milford Sound on 26 April.
• The highest wind gust was 161 km/hr, at Cape Turnagain, on 29 April.
• In April 2013, Tauranga was the wettest, warmest, and sunniest, Dunedin was the coolest, and Christchurch was driest and cloudiest of the six main centres.
• Of the available, regularly reporting sunshine observation sites, the sunniest four centres so far in 2013 (January to April) are: New Plymouth (1118 hours), Whakatane (1097 hours), Paraparaumu (1006 hours), and Lake Tekapo (1003 hours).
-WeatherWatch & NIWA