June 2016 climate summary - 3rd warmest June on record

The 3rd warmest June on record, unusually dry and sunny for many

Overview

During the month of June 2016, air pressure was higher than normal over and to the east of New Zealand while lower than normal pressures existed to the south-west of the country. This pressure set up led to a prevalence of winds from a northerly direction. In addition to frequent winds from the north, warmer than usual sea surface temperatures persisted around New Zealand, especially to the west and north. Much like the past several months, these two factors worked in tandem to bring unusually mild temperatures to the country. As a result, Christchurch and Dunedin had their warmest June on record. Many climate stations in New Zealand recorded above average (0.51°C to 1.20°C) or well above average (>1.20°C) temperatures during June, with several locations experiencing record or near-record warmth (particularly in the South Island). The nationwide average temperature in June 2016 was 10.2°C [Interim value] (1.6°C above the 1981-2010 June average from NIWA’s seven station temperature series which begins in 1909), making June 2016 the 3rd warmest June on record using this series. The first 6 months of 2016 have all been warmer than average and January to June 2016 is the warmest such period in the seven station series temperature history with a departure from average of +1.4°C.

Much like May, the warmer than usual ocean surrounding New Zealand not only contributed to unseasonable warmth on land but also created an environment that was more conducive for strong storms. However, unlike May, record high monthly rainfall was rare, though several one-day maximum or near maximum rainfall extremes did occur, speaking to the isolated nature of the downpours. Much of eastern Southland and Otago received well below normal rainfall (<50%) during the month. Most notably, Nugget Point (Otago) experienced its driest June since records began in 1930. Middle and northern Canterbury, sheltered from a wind that was most predominantly coming from the northwest, also received well below normal rainfall with a small pocket in the Waimakariri and Hurunui Districts observing less than 20% of normal. After a dry start to June, portions of the east coast of the North Island experienced downpours as the month concluded. A few strong areas of low pressure moved from the northwest to southeast across the North Island during the latter stages of the month, resulting in near-record 1-day rainfall in some parts of the eastern North Island. Despite a few rounds of flooding, highlighted by Auckland’s wettest June hour in recorded history on 29 June (25.4 mm), much of the northern North Island received near normal (80-119%) rainfall during June.

Soil moisture levels at the beginning of June were well below normal for this time of year for large parts of Gisborne, Hawke’s Bay, the Wairarapa as well as central and northern parts of Canterbury. Below normal rainfall continued during June for many of these locations, meaning below normal soil moisture levels persisted in these parts. On 1 July 2016, the east coast of both islands continued to exhibit the most abnormally dry soils anywhere in the country with most other places experiencing near normal soil moisture levels for this time of the year.

June sunshine hours were above normal (110-125%) across much of the country with parts of the east coast of both Islands experiencing well above normal (>125%) sunshine. The north of the South Island, south of the North Island, and north of the North Island observed near normal (90-109%) sunshine. Timaru and Balclutha had their second-sunniest June on record while Invercargill had its fourth-sunniest June. Queenstown had its third-sunniest June on record with records dating back to 1930.

Further Highlights:

• The highest temperature was 25.1°C, observed at Napier on 10 June.

• The lowest temperature was -8.2°C, observed at Mt Cook on 7 June.

• The highest 1-day rainfall was 141 mm, recorded at Otamatuna on 22 June.

• The highest wind gust was 172km/h, observed at Cape Turnagain on 10 June.

• Of the six main centres in June 2016, Auckland was the warmest and tied with Wellington as the wettest, Christchurch was sunniest and driest, Tauranga was the cloudiest, and Dunedin was the coolest.

• Of the available, regularly reporting sunshine observation sites, the sunniest four locations in 2016 so far (1 January – 30 June) were Richmond (1440 hours), Blenheim (1324 hours), New Plymouth (1284 hours) and Takaka (1263 hours).

Full climate summary: Climate_Summary_June_2016.pdf

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