- Rainfall: Above average over much of New Zealand; Severe flooding in Otago and Coromandel
- Soil moisture: Significant deficits eliminated in many areas
- Temperature: Warm, highest nationally since 1981, and 8th highest in reliable records
- Sunshine: Very sunny in Gisborne, rather cloudy in North Westland
Flood-producing rainfall events occurred in north and east Otago over 25/26 April, and in the Hauraki-Coromandel region over 27/28 April. As a result the month’s rainfall was very high in these regions. Rainfall in north and east Otago totalled 300-400 percent (three to four times) of normal, and totals in the Hauraki-Coromandel region were at least 200 percent (two times) of normal. Rainfall was also well above normal in Northland, Auckland, Waikato, Bay of Plenty, Taupo, north Westland, Nelson, the Southern Alps, inland South Canterbury, and inland areas of Southland. Hokitika recorded its highest April rainfall since 1920. Severe soil moisture deficits were eliminated in many areas. April was much warmer than usual, with mean temperatures being the highest since 1981, and 8th highest since reliable records in the 1860s. The national average temperature of 14.6 °C (higher than March) was 1.2 °C above the 1971-2000 normal. April was much sunnier than normal in Gisborne. However, sunshine was below normal in north Westland and Nelson. During April, depressions (or 'lows') were much more frequent than average in the Tasman Sea. This pattern resulted in frequent warm northwesterlies over the North Island, and more northeasterlies than normal over the South Island.
Other Highlights
- The highest temperature recorded during April 2006 was 29.0 °C recorded in Napier on the 3rd. The lowest temperature for the month was -2.0 °C at Middlemarch, Otago on the 14th.
- Tornado-like winds damaged property on the Kapiti coast during the morning of 8 April, and at Leamington (Waikato) on 20 April.
- The highest wind gust recorded was 128 km/h from the northwest at South West Cape on the 23rd.
- High rainfall in Papakura, Auckland on 18 April, with flooding forcing people to evacuate their homes.
- Severe flooding over 25/26 April in north and east Otago. Much of the Taieri Plains, including Mosgiel, was flooded, as well as the towns of Oamaru and Waitati. Motorists were stranded overnight in their cars. The same weather system brought heavy snowfall to the Remarkables in west Otago, as well as Coronet Peak and Cardrona.
- More flooding in the Hauraki/Coromandel and Auckland regions over 27/28 April. Floodwaters resulted in the closure of the Karangahake Gorge Road between Paeroa and Waihi, and SH26 between Paeroa and Te Aroha. Flooding also occurred in Whangamata, Pauanui, and Auckland’s North Shore.
- Temperatures were above average in all five main centres. Christchurch was the driest and sunniest, and Auckland easily the wettest of the main centres. Rainfall was above average in Auckland, Hamilton, Christchurch, and Dunedin, near average in Wellington. Sunshine hours were above average in Christchurch, below average in Hamilton, and near average in the three other main centres.
Rainfall
Rainfall was 300-400 percent of normal in parts of north and east Otago, and about 200-250 percent of normal in parts of Northland, Auckland, Hauraki-Coromandel, Waikato, Bay of Plenty, Taupo, North Westland, Nelson, the Southern Alps, inland South Canterbury, and inland areas of Southland. Rainfall was also above average in many other northern and western regions, as well as Hawke’s Bay and central Marlborough. In contrast, April rainfall totals were 50 percent (half) or less of normal in southern parts of Wairarapa and the Kaikoura coast, and also below normal in coastal Southland.
Temperature
Mean temperatures were about 1.5 °C above average throughout much of the North Island, and 2 °C or more above average in parts of Auckland and Coromandel. Temperatures were 1 to 2 °C above average throughout much of the South Island, and more than 2 °C above average in parts of Canterbury and Otago.
Sunshine
Sunshine hours and/or solar radiation were more than 120 percent of normal in Gisborne, and also above normal in parts of Northland, Canterbury and Southland. In contrast, they were well below normal in North Westland and Nelson.
Full report
- Full details of the April 2006 Climate Summary
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.