Warmest June on record for New Zealand

Temperature	It was an exceptionally warm start to winter in terms of both intensity and coverage with just about all of New Zealand, from the top of the North Island to the bottom of the South Island, reporting above normal (0.51-1.20°C above average) to well above normal (more than 1.20°C above average) temperatures for June. In fact, dozens of climate stations placed in the top four for warmest June ever recorded, with New Zealand’s Seven Station Series recording the warmest June on record of 10.3°C.
Rainfall	Early winter rain was above normal (120-149% of June normal) to well above normal (150% or greater of the June normal) for most of the Northland, Auckland, Waikato and coastal Bay of Plenty regions. Conversely, below (50-79% of June normal) to well below normal rainfall (less than 50% of June normal) for much of the Taranaki, interior Bay of Plenty, and south coastal Hawke’s Bay as well as much of the Manawatu-Wanganui regions. South Island rainfall was just as wide ranging with parts of eastern Canterbury, coastal Marlborough and Nelson regions receiving above or well above normal rainfall for June. Meanwhile, below or well below rainfall was recorded in a good part of the Otago and Southland regions. Most other locations in New Zealand received near normal June rainfall (within 20% of normal).
Soil Moisture	As of 1 July 2014, after a very dry summer for much of the North Island, soil moisture levels are now at typical levels for this time of year for most locations. The exception is parts of the Hawke’s Bay where some coastal areas are drier or much drier than normal for this time of year. Soils remain quite saturated for most of the eastern part of the South Island, in particular coastal Marlborough, Canterbury and northern parts of the Otago regions. All other parts of the South Island have soil moisture levels that are typical for this time of year.
Sunshine	Sunshine was near normal (90 to 109% of normal) for much of the North Island. However, the central North Island from Taumarunui to Palmerston North received well above normal sunshine (more than 125% of June normal) to begin the winter season. Most of the South Island also received near normal sunshine; however, there were also exceptions with pockets of below normal sunshine (75 to 89% of June normal) over the Otago region with spotty areas of well below normal (less than 75% of June normal) sunshine over coastal Southland.

Overview

June 2014 was characterised by higher than normal mean sea level pressure (MSLP) values from New Zealand, and in particular, points east and southeast of the country to the Dateline. Meanwhile, lower than normal MSLP were present to the west and southwest of New Zealand. This resulted in a dominant north-easterly flow anomaly across the country. Furthermore, this played a significant role in the record warm June, and start to the winter season, as this meant the source origin of air was not from the higher latitudes where colder air is generated.

The persistent lack of southerlies not only had a profound impact on the monthly temperatures in terms of the strength, or departure from average, but also the coverage. In fact, only one climate station (Middlemarch) experienced a June mean temperature that was NOT either above average (0.51 to 1.2°C above June average) or well above average (more than 1.2°C above June average). As highlighted in the temperature section of this document, dozens of locations experienced record or near record warm temperatures in June.

As for rainfall, there was quite a contrast in terms of distribution across the country. Many northern and eastern parts of the North Island received above normal or well above normal rainfall for June (110-125% of normal and greater than 125% of normal, respectively) from Northland to Auckland and Bay of Plenty regions. However, rainfall was lacking for many other parts of the North Island, in particular the Taranaki, Manawatu-Wanganui, Wairarapa and southern coastal areas of the Hawke’s Bay regions where rainfall was below normal (50-79% of June normal) or well below normal (less than 50% of June normal). No doubt the prevailing north-easterly wind, described earlier, carrying warmth and moisture from the sub-tropics and tropics, substantially contributed to this rainfall pattern as northern and eastern areas first greeted the moist air and thus releasing much of its water content in said areas. Moreover, it is distinctly possible - if not likely - that rainfall was further enhanced by abnormally warm sea surface temperatures (up to 1.0°C above normal) east of New Zealand as that provided additional fuel for low pressure centres. The wet impacts of the northeast wind then reversed as the air continued to travel southwest (from the northeast), drying significantly by the time it reached central and southern parts of the island.

The rainfall dichotomy continued across the Cook Strait and onto the South Island where precipitation ranged from above normal to well above normal from the Tasman and Marlborough regions south into eastern Canterbury and continuing to the Christchurch region. Interestingly, just southeast of Christchurch, on the Banks Peninsula, rainfall was very low with Akaroa receiving only one-third of the June normal rainfall, or well below normal (less than 50% of June normal). The checkerboard pattern continued farther south into the rest of the South Island as woven into a regime of below normal or well below normal rainfall were areas of normal to even well above normal rainfall. Of note were many Southland areas that experienced an unusually dry June, with several locations reporting below or well below normal June rainfall. A relative lack of onshore (south to southwest) airflow is likely to be a contributing factor to these observations. 

In spite of the somewhat erratic nature of the June rainfall distribution, soil moisture levels were more uniform, though regions of abnormally wet or dry soils were present. As of 1 July, most of the country has soil moisture levels that are, generally speaking, close to normal (i.e. near field capacity) for this time of year. The exceptions are on eastern areas of both islands where parts of Hawke’s Bay, coastal Wairarapa are reporting soil moisture levels that abnormally dry for this time of year. For the South Island, abnormally wet soils for this time of year are present from the eastern Marlborough south through to coastal Otago regions.

Near normal (within 10% of June normal) or above normal (110-125% of June normal) June sunshine hours were recorded for most parts of the North Island. There were even few locations that experienced well above average sunshine for the month (more than 125% of June normal), mostly in the Manawatu-Whanganui region.  Sunshine for the South Island was, on average, comparatively less plentiful.  Much of the island experienced near normal (within 10% of June normal) or below normal sunshine (75-89% of June normal), with well below normal sunshine recorded in Nelson (less than 75% of June normal). However, nestled within that zone was Cheviot in northern Canterbury, which received well above normal sunshine for June. Well above normal sunshine was also experienced in Queenstown.

Further Highlights:

• The highest temperature was 22.2°C, observed at Waione on 8 June.
• The lowest temperature was -7.4°C, observed at Hanmer Forest on 1 June.
• The highest 1-day rainfall was 137 mm, recorded at Te Puke on 11 June.
• The highest wind gust was 161 km/hr, observed at Cape Turnagain on 21 June.
• Of the six main centres in June 2014, Dunedin was the driest and cloudiest, Auckland was the sunniest and warmest, Tauranga was the wettest, and Christchurch was the coolest.
• Of the available, regularly reporting sunshine observation sites, the sunniest four centres[1] so far in 2014 (January to June) are: Whakatane (1392 hours), Tauranga (1261 hours), Auckland - Albany (1214 hours) and Takaka (1207 hours).

 Download the full report:

Climate Summary for June 2014

Climate statistics table

Climate statistics for June 2014

For further information, please contact:

Mr Chris Brandolino

NIWA Forecaster – NIWA National Climate Centre

Tel. 09 375 6335, Mobile (027) 886 0014