Climate summary for December 2016

A dry end to the year with average to below average temperatures.

Rainfall 

Rainfall was below normal (50-79% of normal) or well below normal (<50% of normal) for the majority of the country during December. The exceptions were the western fringes of Southland, the West Coast, Tasman and Wellington regions where rainfall was near normal (80-119% of normal). Above normal rainfall (120-149% of normal) was recorded at a handful of locations.

Soil Moisture 

At the end of December 2016, soil moisture levels were below normal for the time of year for much of the North Island with the driest soils compared to normal located in the Far North. Soils were also slightly drier than normal about Southland and Otago with the remainder of the South Island seeing near normal soil moisture levels.

Sunshine

Sunshine was well above normal (>125% of normal) in the north and west of the North Island as well as parts of the West Coast, Southland and Otago. Sunshine was near normal (90-109% of normal) or above normal (110-125% of normal) for the remainder of the country.

Temperature

 

December temperatures were below average (-1.20°C to -0.51°C of average) for parts of Waikato, Taranaki, Wellington, Tasman and the West Coast. The remainder of the country experienced near average (-0.50 to +0.50°C of average) temperatures.

Overview

December was characterised by lower than normal pressure to the south of New Zealand and the frequent passage of highs over the North Island. This pressure anomaly led to slightly more westerly and southwesterly winds than normal across the country.

Drier December for most areas

After a wet November, December rainfall was quite the opposite, with the majority of the country observing below normal (50-79% of the December normal) or well below normal (<50% of the December normal) rainfall amounts. Some of the lowest December rainfall totals were recorded in Northland with Kerikeri seeing just 9mm of rain (or 8% of normal), its lowest December rainfall on record with records extending back to 1935. The exceptions to the low rainfall were the western fringes of Southland, the West Coast, Tasman and Wellington regions where rainfall was near normal (80-119% of the December normal). Above normal rainfall (120-149% of the December normal) was recorded at a handful of locations.

Sunny but drier soils 

The lack of meaningful rain throughout the month meant that sunshine was plentiful with no locations observing below normal sunshine hours (75-89% of the December normal) or lower. Near normal sunshine hours (90-109% of the December normal) were recorded about Nelson, Marlborough, Wellington and Thames-Coromandel with the remainder of the country seeing above normal (110-125% of the December normal) or well above normal (>125% of the December normal) sunshine hours. Both Kaitaia and Dunedin experienced their second sunniest Decembers on record.

The lack of rainfall during December and sunny skies meant that soil moisture levels dropped drastically across the majority of the country throughout the month. The unlikely exception to this was coastal Hurunui where soil moisture levels increased and are now only slightly below normal for this time of year. This part of the country has seen drought conditions throughout much of 2015 and 2016. As of 1 January, soil moisture levels were below normal for this time of year for much of the North Island with the driest soils compared to normal located in the Far North. Soils were also slightly drier than normal about Southland and Otago with the remainder of the South Island seeing near normal soil moisture levels.

Average temperatures for many locations

Despite the sunny skies, winds from a westerly to southwesterly direction kept temperatures on the mild side. In most locations, temperatures were near average (-0.50 to +0.50°C of average). However, pockets of below average temperatures (-1.20°C to -0.51°C of average) were found in Waikato, Taranaki, Wellington, Tasman and parts of the West Coast. December was the only month of the year where no climate stations observed record or near-record high monthly mean temperatures. The nationwide average temperature in December 2016 was 15.4°C (0.3°C below the 1981-2010 December average from NIWA’s seven station temperature series which begins in 1909).

Further highlights

  • The highest temperature was 33.2°C, observed at Christchurch (Riccarton) on 21 December.
  • The lowest temperature was -1.2°C, observed at Hanmer Forest on 20 December.
  • The highest 1-day rainfall was 152.2 mm, recorded at Takaka on 7 December.
  • The highest wind gust was 161 km/hr, observed at Akitio on 15 December.
  • Of the six main centres in December 2016, Wellington was the wettest, Auckland was the warmest and driest, Dunedin was the coolest. Tauranga was the sunniest and Christchurch was the least sunny.
  • Of the available, regularly reporting sunshine observation sites, the sunniest four locations in 2016 (1 January – 31 December) were Richmond (2840 hours), Blenheim (2582 hours), Takaka (2534 hours) and New Plymouth (2503 hours).

Download

Complete climate summary for December 2016 [PDF 513KB]

Climate Statistics for December 2016 [PDF 69 KB]

Contacts

For further information, please contact:

Mr Chris Brandolino, Principal Scientist – Forecasting, NIWA National Climate Centre
Tel. 09 375 6335, Mobile 027 886 0014