Autumn 2014

A warm and sunny autumn for much of the North Island, wet for many parts of the South Island.

Rainfall 

It was a wet autumn for much of the South Island and parts of the lower North Island.  Autumn rainfall was well above normal (more than 150% of normal) in south-western Southland, and along the eastern South Island near Dunedin and north of Timaru.  Autumn rainfall was above normal (120-150% of normal) in Nelson, Marlborough, many remaining parts of Canterbury and Otago, and inland Southland.  In contrast, rainfall was below normal (50-79% of autumn normal) for Northland, Auckland, and the Coromandel Peninsula, as well as in parts of Gisborne, Hawke’s Bay and Taranaki.  Remaining areas of New Zealand typically received near normal autumn rainfall (within 20% of autumn normal).

Soil moisture

At the start of autumn, soils were much drier than normal across most of the North Island.  Welcome autumn rainfall saw an improvement in soil moisture levels across many parts of the North Island, but as of 1 June 2014, drier than normal soils persist for parts of Auckland and Northland, whilst soils about northern Gisborne, the Central Plateau and Hawke’s Bay were also drier than normal.  As of 1 June 2014 soils were wetter than normal throughout the eastern South Island, the Southern Lakes and Central Otago, whilst soil moisture levels were near normal for most remaining areas of the country.

Temperature

Autumn temperatures were near average (within 0.5°C of the autumn average) for much of Northland, Auckland, Mahia Peninsula, coastal Wairarapa, Wellington, Marlborough, Canterbury, eastern Otago and the Catlins.  Autumn temperatures were above average (0.5°C to 1.2°C above average) or well above average (more than 1.2°C above average) for remaining areas of the country.      

Sunshine

Autumn sunshine was abundant for most of the North Island, where above normal (110-125% of autumn normal) or well above normal (more than 125% of autumn normal) sunshine was received.  The exception was towards and along the south-western coast of the island from Taranaki to Wellington, where sunshine was near normal (within 10% of autumn normal) or below normal (75-89% of autumn normal).  Below normal or near normal sunshine for autumn was received across the entire South Island.

Overview

As a whole, autumn 2014 was characterised by pressure anomalies that were very weak over most of the country, with slightly higher than normal pressures recorded to the southeast of New Zealand.  This pattern resulted in a weak south-easterly flow anomaly.  March was characterised by anomalously high pressure anomalies over much of New Zealand, which exacerbated dry conditions being experienced over the North Island at the time.  April saw a north-easterly quarter wind flow anomaly over most of the country, which brought welcome rain to North Island parts, but considerable rainfall and flooding to eastern and northern parts of the South Island.  The frequency of westerly flows across New Zealand was higher than is usual in May, which contributed to a dry and sunny end to autumn for much of the North Island.

Rainfall for the autumn season was well above normal (more than 150% of normal) in south-western Southland, and along the eastern South Island near Dunedin and north of Timaru.  It was especially wet in coastal parts from Christchurch to Kaikoura where autumn rainfall totals recorded were more than double that which normally occurs.  Autumn rainfall was above normal (120-150% of normal) in Nelson, Marlborough, many remaining parts of Canterbury and Otago, and inland Southland.  In contrast, rainfall was below normal (50-79% of autumn normal) for Northland, Auckland, and the Coromandel Peninsula, as well as in parts of Gisborne, Hawke’s Bay and Taranaki.  It was an especially dry autumn for Kerikeri and Whangarei, with both locations recording around half of normal autumn rainfall.  Remaining areas of New Zealand typically received near normal autumn rainfall (within 20% of autumn normal).

At the beginning of March, much of the North Island had experienced a relatively dry summer, and soils were much drier than normal for the time of year.  Welcome autumn rainfall saw an improvement in soil moisture levels across many parts of the North Island, but as of 1 June 2014, drier than normal soils persist for parts of Auckland and Northland, whilst soils about northern Gisborne, the Central Plateau and Hawke’s Bay were also drier than normal.  In contrast, as of 1 June 2014 soils were wetter than normal throughout the eastern South Island, the Southern Lakes and Central Otago.  The wetter than normal soils about eastern Canterbury were as a result of considerable rainfall occurring in March and April.  For example, parts of Christchurch received 71% of the city’s average annual rainfall over those two months.  As of 1 June 2014, soil moisture was near normal for most remaining parts of New Zealand.

Autumn temperatures were near average (within 0.5°C of the autumn average) for much of Northland, Auckland, Mahia Peninsula, coastal Wairarapa, Wellington, Marlborough, Canterbury, eastern Otago and the Catlins.  Autumn temperatures were above average (0.5°C to 1.2°C above average) or well above average (more than 1.2°C above average) for remaining areas of the country.  The above average autumn temperatures recorded across New Zealand largely resulted from an abnormally warm April, when temperatures for a significant part of the country were well above average (more than 1.2°C above April average).  The nation-wide average temperature in autumn 2014 was 13.7°C (0.5C° above the 1971-2000 April average from NIWA’s seven station temperature series which begins in 1909).

Autumn sunshine was abundant for most of the North Island, where above normal (110-125% of autumn normal) or well above normal (more than 125% of autumn normal) sunshine was received.  The exception was towards and along the south-western coast of the island from Taranaki to Wellington, where sunshine was near normal (within 10% of autumn normal) or below normal (75-89% of autumn normal).  Autumn sunshine wasn’t quite so prevalent in the South Island, with below normal or near normal sunshine received across the entire island.

Further Highlights:

  • The highest temperature was 30.8°C, observed at Wallaceville (Upper Hutt) on 16 March.
  • The lowest temperature was -7.4°C, observed at Middlemarch on 30 May.
  • The highest 1-day rainfall was 256 mm, recorded at Milford Sound on 22 May. 
  • The highest wind gust was 202 km/hr, observed at Cape Turnagain on 25 May.
  • Of the six main centres in autumn 2014, Auckland was the warmest and driest, Tauranga was the sunniest, Dunedin was the coolest and cloudiest, and Wellington was the wettest.
  • Of the available, regularly reporting sunshine observation sites, the sunniest four centres so far in 2014 (January to May) are: Whakatane (1262 hours), Tauranga (1153 hours), Auckland - Albany (1090 hours) and Takaka (1077 hours).

Full report

Autumn 2014 climate summary

For further information, please contact:

Mr Chris Brandolino
NIWA Forecaster – NIWA National Climate Centre
Tel. 09 375 6335, Mobile (027) 866 0014