Summer 2013-14

Changeable summer temperatures, dryness ends the season in the North Island.

Rainfall  

Rainfall for summer was below normal for much of the North Island (between 50-80 percent of normal) especially western Northland, all of the Waikato (excluding the Coromandel Peninsula) and Ruapehu District.  Areas that were particularly affected by the dryness include the western coastal Waikato, southeast through to northern portions of the Manawatu-Wanganui region.  Eastern Northland received above normal rainfall (120-150 percent of normal summer rain) with near normal rainfall for other locations of the North Island (within 20 percent of normal).  Below normal rainfall (50-80 percent of normal) occurred from Blenheim to Nelson as well as Timaru and Queenstown Lakes District.  The remainder of the South Island recorded near normal rainfall (within 20 percent of normal) with some sections receiving above normal rainfall.

Temperature

Summer temperatures were near average for most of the country (within 0.5°C of the summer average).  There were a few areas of below normal temperatures on both islands such as parts of the Waikato and from Hokitika to Haast as well as parts of central Otago and Dunedin (between 0.5 and 1.2°C below average).  Motu in the Bay of Plenty region recorded above average temperatures (between 0.5 and 1.2°C above average) as well as Akaroa in the South Island. 

Soil Moisture

As at 1 March 2014, soils were much drier than normal across the North Island, except for eastern Northland and the coast south of Hawke’s Bay where soils are slightly wetter than normal for time of year.  Drier than normal soils for much of the interior of the South Island, particularly Tasman, Marlborough and much of Canterbury and Southland regions.  Western coastal areas and around Banks Peninsula have slightly wetter than normal soils for this time of year.  

Sunshine

Sunshine for the summer was abundant for the Far North, central North Island and inland Canterbury where above normal sunshine was recorded (110 to 125 percent of summer normal). Much of the remainder of the country experienced near normal sunshine (within 10 percent of summer normal).

Overview 

As a whole, lower pressures than normal dominated the New Zealand region from December to February.   Wind flow during the season was quite variable with a weak northerly flow present in December, followed by a strong southwesterly flow anomaly in January.  The said flow in December contributed to a very warm start to the summer season with decidedly cooler and unsettled weather following in January.  With the predominant wind shifting into the southeast in February, there was an intensification of the unusually dry conditions for the western and central North Island. 

Rainfall for the summer season was below normal for much of the North Island (between 50-80 percent of normal summer rainfall), especially the western Northland, all of the Waikato (excluding the Coromandel Peninsula) and Ruapehu District.  Areas that were particularly affected by the dryness include the western coastal Waikato, southeast through to northern portions of the Manawatu-Wanganui region where Turangi and Ohakune recorded approximately 40% of normal summer rainfall.  An exception was eastern Northland where Kerikeri received above normal rainfall (120-150 percent of normal summer rain).  Areas of the North Island receiving near normal rainfall included Hicks Bay, Castlepoint and Wellington (within 20 percent of normal summer rainfall). 

For the South Island, below normal rainfall (50-80 percent of normal) occurred in northern sections from Blenheim to Nelson as well as Timaru and Queenstown Lakes District.  The remainder of the South Island recorded near normal rainfall (within 20 percent of normal) except for Kaikoura and Oamaru which recorded above normal rainfall and Ranfurly which received well above normal rainfall (more than 150 percent of normal). 

The summer season started off on a warm note throughout the country whereas January was quite a bit cooler and February ended on an average note.  Therefore, temperatures this past summer collectively ended up being near average for most of the country (within 0.5°C of the summer average).  There were a few areas of below normal temperatures on both islands such as parts of the Waikato and from Hokitika to Haast, as well as parts of central Otago and Dunedin (between 0.5 and 1.2°C below average).  On the other side of the spectrum, Motu in the Bay of Plenty region recorded above average temperatures (between 0.5 and 1.2°C above average) as well as Akaroa in the South Island.  The nation-wide average temperature in summer 2013-2014 was 16.7°C (equal to the 1971-2000 summer average), using NIWA’s seven-station temperature series which begins in 1909. 

As at 1 March 2014, soils were much drier than normal across the North Island, except for eastern Northland and the coast south of Hawke’s Bay where soils are slightly wetter than normal for time of year.  Soils were drier than normal for much of the interior of the South Island, particularly Tasman, Marlborough and much of Canterbury and Southland regions.  Western coastal areas and around Banks Peninsula have slightly wetter than normal soils for this time of year.   Soil moisture deficits are not as extensive as those a year ago in the 2013 drought, but may be as severe as 2013 in isolated regions. Soil moisture levels are lowest, relative to normal at this time of year, in the Waikato, Waitomo and Taupo districts.

Sunshine for the summer was abundant for the Far North, central North Island and inland Canterbury where above normal sunshine was recorded (110 to 125 percent of summer normal). Much of the remainder of the country experienced near normal sunshine (within 10 percent of summer normal).

Further highlights: 

  • The highest temperature was 35.7°C, recorded at Clyde on 20 February.
  • The lowest temperature was -2.7°C, observed at Waiouru on 27 January.
  • The highest 1-day rainfall was 220 mm, recorded at North Egmont on 4 January. 
  • The highest wind gust was 183 km/hr, at Cape Turnagain on 16 January.
  • In summer 2013-2014, Auckland was the warmest, Tauranga was the wettest and sunniest, Christchurch was the driest with Dunedin the coolest and cloudiest of all the main centres. 

Full report 

Full details of the Summer 2013-14 climate summary (PDF 690 KB)

For further information, please contact: 

Dr Brett Mullan
Principal Scientist, Climate, NIWA Wellington
Tel. 04 386 0508