Autumn 2012

Dry and record sunny over South Island.

Autumn was characterised by higher pressures than normal southeast of New Zealand, and extending across the South Island. Lower pressures than usual were observed north of the country, resulting in more easterly quarter winds than usual over the North Island.  The higher than usual pressures over the South Island resulted in a very dry month there, while the easterly winds contributed to below average temperatures in eastern regions.

It was a dry autumn over the South Island, with less than three quarters of normal autumn rainfall recorded for most regions (the exception being the Kaikoura Coast, with near normal rainfall).  Notably dry were Canterbury and parts of Nelson, with less than half of seasonal normal rainfall observed.  It was also rather dry for Manawatu-Wanganui and the Tararua District. In contrast, above normal rainfalls were recorded in Northland, north Auckland, Gisborne, parts of Hawkes Bay, and the south Wairarapa coast.  Elsewhere, rainfalls were near normal.  At the end of autumn, soils were much drier than normal for the time of year in Canterbury and Nelson, as well as the Tararua District and around Palmerston North.  

Autumn was extremely sunny over the South Island, and for the western North Island between Waikato and Taranaki, with many records set.  Sunshine totals were also above normal in most other regions.  The exceptions were Northland, Coromandel, Wellington and the eastern North Island (Gisborne, Hawkes Bay, Wairarapa), which experienced near normal sunshine totals.

Mean temperatures for autumn were below average across the north and east of the South Island, and for much of the North Island south of Taupo.  Autumn temperatures were near average (within 0.5°C of the autumn average) elsewhere, namely in the southwest of the country (Southland, Fiordland, Westland), as well as in Taranaki, around Wanganui, Bay of Plenty, Coromandel, and parts of Waikato, Auckland and Northland.  Morning (minimum) temperatures across the country showed much the same pattern; but were near-record low for autumn at many eastern or inland locations. The nation-wide average temperature in autumn was 12.9°C (0.4°C below the 1971–2000 autumn average), using NIWA’s seven-station temperature series which begins in 1909.  

Further highlights: 

• The highest temperature experienced was 29.2°C, observed at Timaru on 24 March.
• The lowest temperature experienced was -8.1°C, recorded at Ranfurly on 20 May. 
• The highest 1-day rainfall experienced was 207 mm, recorded at North Egmont on 27 May. 
• The highest gust recorded was 158 km/hr at Brothers Island, Cook Strait, on 3 March.
• Of the six main centres in autumn, Auckland was the warmest, Tauranga the sunniest, Wellington the wettest and cloudiest, and Christchurch the coolest and driest.

Full report

Autumn 2012 climate summary (PDF 110 KB)

For further information, please contact:

Ms Georgina Griffiths – Climate Scientist– NIWA National Climate Centre, Auckland, 

Mobile 0272 936545