A mild autumn for most of the country

Temperature	Autumn temperatures were above average (+0.51°C to +1.20°C) for many parts of the country. It was a particularly warm autumn in parts of eastern Canterbury, West Coast and Taranaki where temperatures were well above average (> +1.20°C). Temperatures were near average (-0.50°C to +0.50°C) in southeastern parts of Southland and Otago, inland mid-Canterbury and parts of the central North Island.
Rainfall	Rainfall was below normal (50-79%) or well below normal (< 50%) for some eastern areas of New Zealand including South Canterbury, North Canterbury, Wairarapa, northern Hawke’s Bay and Gisborne. Rainfall was either above normal (120-149%) or well above normal (> 149%) for southwestern and western parts of both the South Island and North Island, and much of Waikato.
Soil moisture	As of 1 June 2015, soil moisture levels were below normal for this time of year for East Cape, coastal Wairarapa, southern Marlborough and eastern parts of Canterbury. It was especially dry about North Canterbury where soils were considerably drier than normal for this time of year.
Sunshine	Autumn sunshine was above normal (110-125%) for the eastern Bay of Plenty, East Cape, Gisborne, Hawke’s Bay and eastern North Canterbury where autumn sunshine. Most remaining areas of New Zealand received near normal sunshine (90-109%). The exception was parts of Taranaki and the West Coast where autumn sunshine was below normal (75-89%).

Overview

Autumn temperatures were predominantly above average (0.51°C to 1.20°C above the autumn average) for the South Island, and the lower and upper North Island. 

It was an especially warm autumn for isolated parts of inland Taranaki, eastern Canterbury and the West Coast where temperatures were well above average (> 1.20°C above the autumn average).

Temperatures were in the near average range (-0.50°C to +0.50°C) for southeastern parts of Southland and Otago, inland mid-Canterbury, and the central North Island including north Taranaki, Central Plateau and East Cape. 

The nation-wide average temperature in autumn 2015 was 14.0°C (0.8°C above the 1981-2010 autumn average, using NIWA’s seven-station temperature series which begins in 1909) (interm value).

Air pressure

Pressures were below normal over New Zealand and the Tasman Sea during autumn, resulting in an anomalous westerly quarter airflow. This airflow anomaly was reflected in the distribution of rainfall anomalies observed across New Zealand. Specifically, rainfall was below normal (50-79% of the autumn normal) or well below normal (< 50% of the autumn normal) for some eastern areas of New Zealand including South Canterbury, North Canterbury, Wairarapa, northern Hawke’s Bay and Gisborne. 

Rainfall

In contrast, rainfall was plentiful for many western parts of New Zealand. Rainfall was either above normal (120-149% of autumn normal) or well above normal (> 149% of the autumn normal) for southwestern and western parts of both the South Island and North Island, and much of Waikato. Kapiti Coast observed an especially wet autumn, with parts of the region receiving in excess of 200% of normal autumn rainfall. Rainfall was typically near normal (80-119% of the autumn normal) for remaining areas of the country. As of 1 June 2015, soils were notably drier than normal for East Cape, coastal Wairarapa, southern Marlborough and eastern parts of Canterbury. Elsewhere, soil moisture levels were nearer to normal for this time of year, with the exception of northwestern Southland, where soils were wetter than normal.

Sunshine

It was a sunny autumn in the eastern Bay of Plenty, East Cape, Gisborne, Hawke’s Bay and eastern North Canterbury where autumn sunshine was above normal (110-125% of the autumn normal).  Remaining parts of the country typically received near normal sunshine (90-109% of the autumn normal), with autumn sunshine below normal (75-89% of the autumn normal) for parts of Taranaki and the West Coast.

Further highlights

Further highlights include: 

• The highest temperature was 32.1°C, observed at Hanmer Forest on 5 March.
• The lowest temperature was -9.0°C, observed at Hanmer Forest on 28 May.
• The highest 1-day rainfall was 206 mm, recorded at North Egmont 8 April.
• The highest wind gust was 178km/hr, observed at Cape Turnagain on 13 May.
• Of the six main centres in autumn 2015, Auckland was the warmest, Dunedin was the coolest and cloudiest, Christchurch was the driest, Hamilton was the wettest and Tauranga was the sunniest.
• Of the available, regularly reporting sunshine observation sites, the sunniest four centres so far in 2015 (1 January to 31 May) are: Whakatane (1200 hours), Blenheim (1182 hours), Waipara West (1173 hours) and Appleby (1173 hours).

Download

Climate Summary Autumn 2015 [PDF 706KB]

Climate Summary Autumn 2015 [DOC 644KB]

Contact

For further information, please contact:

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