Warm and wet for many regions.
- Temperatures: Above average autumn temperatures for much of the North Island, as well as the north of the South Island. Near average temperatures over the southern half of the South Island. Several heat waves during the autumn.
- Rainfall: Above normal autumn rainfall across most of the North Island, as well as the north of the South Island, Otago and south Canterbury.
- Sunshine: A cloudy autumn for Otago, Nelson, Taranaki to Wellington. Near normal autumn sunshine in most other regions.
New Zealand was affected by more northerly winds than usual during autumn, squeezed between low pressures over the Tasman Sea and anticyclones (‘highs’) lying east of the country. These northerly winds contributed to the very warm and wet autumn experienced over most of the North Island, and the north of the South Island.
Autumn temperatures were well above average (more than 1.2°C above the autumn average) in parts of Northland, Auckland, the Firth of Thames and Bay of Plenty, southern Hawkes Bay, and around Nelson. Elsewhere in the North Island, and in the north of the South Island, autumn temperatures were generally above average (between 0.5°C and 1.2°C above the autumn average). Near average autumn temperatures (within 0.5°C of average) were experienced over the southern half of the South Island. Using NIWA’s seven-station temperature series, the average temperature for autumn 2011 was 13.9°C (0.6°C above the 1971–2000 autumn average).
Rainfall totals for autumn were well above normal (exceeding 150 percent of autumn normal) in parts of Northland, Auckland, Coromandel, Waikato, Bay of Plenty, Gisborne, Central Plateau, Hawkes Bay, from Taranaki to Kapiti Coast, Nelson, Tasman District, south Canterbury and Otago. Elsewhere in the North Island, autumn rainfalls were generally above normal (between 120 and 149 percent of autumn normal). Across the remainder of the South Island, autumn rainfall totals were close to normal (ranging between 80 and 119 percent of seasonal normal).
It was a rather cloudy autumn for Otago and the Lakes District, around Nelson, and from Taranaki to Wellington (with sunshine totals less than 90 percent of autumn normal). Elsewhere, autumn sunshine was closer to seasonal normal (between 90 and 115 percent of autumn normal).
Autumn climate was rather extreme: A State of Emergency was declared for Hawkes Bay on 28 April, due to flooding and slips in the region following extremely heavy rainfall on 26-28 April, and several coastal Hawkes Bay settlements were evacuated after being completely cut off. May started with a heat wave on the West Coast of the South Island. A tornado swept through Albany (Auckland) on 3 May. Flooding rains affected Otago on May 7/8, and Nelson and Takaka on May 25/26.
- The highest temperature recorded was 31.4°C recorded at Christchurch on 4 March.
- The lowest temperature recorded was -5.9°C recorded at Ranfurly on 28 April.
- The highest 1-day rainfall of 289 mm was recorded at North Egmont on 25 May.
- The highest gust was 184 km/hr recorded at Southwest Cape on 12 May.
- Of the six main centres, Tauranga was the wettest but also the sunniest, Auckland was the warmest, Christchurch the driest, and Dunedin the coolest and cloudiest.
Autumn 2011 climate summary (PDF 86 KB)
For further information, please contact:
Ms Georgina Griffiths – Climate Scientist
NIWA National Climate Centre - Auckland