February 2017 Climate Summary

Wet for some of the North Island, dry for the South Island

Overview

February 2017 was characterised by higher than normal atmospheric pressure over much of New Zealand with lower than normal pressure to the southwest. This pressure pattern resulted in more winds from a northwesterly direction than normal.

While the month got off to a dry start, several storms in mid-February caused wetter than normal conditions for the month as a whole across much of the North Island. Northland received near normal (80-119% of normal) rainfall around Kaipara and Whangarei, and above normal (120-149% of normal) to well above normal (>149% of normal) rainfall in the Far North. Rainfall in the Wellington, Waikato and Bay of Plenty regions as well as in southern Hawke’s Bay was above normal or well above normal with Hastings receiving 237% of its normal February rainfall, experiencing its fourth wettest February on record at this location. Much of the rest of the North Island received near normal (80-119% of normal) rainfall totals. In stark contrast, most of the eastern South Island was drier than normal for February, experiencing below normal (50-79% of normal) to well below normal (<50% of normal) rainfall totals. The exceptions to this were southern Canterbury where near normal rainfall was observed, and eastern Marlborough where rainfall was well above normal. Most of the western South Island received near normal or below normal rainfall.

February temperatures were above average (+0.50°C to +1.20°C) in Northland and much of the eastern North Island with well above average (>1.20°C) temperatures observed at stations in Whangarei and Wairoa. Other parts of the North Island were largely characterised by near average (-0.50°C to +0.50°C) temperatures. Most of the South Island experienced near average temperatures, although above average temperatures were recorded in Central Otago, Hurunui, and Christchurch. Below average (-0.51°C to -1.20°C) temperatures were observed in western Southland and well below average (<-1.20°C of average) were observed in the north of the Tasman District.

After a dry December through to early February, the Minister of Primary Industries officially classified the impact of Northland’s drought as a medium-scale adverse event under the Primary Sector Recovery Policy. Soil moistures in February, however, were higher than normal in central and southern parts of the North Island, and also in the Far North. Much of coastal Taranaki and part of Northland experienced soil moisture levels that were below normal. Due to limited rainfall, much of the South Island experienced below normal soil moistures except for a large area around Otago where average soil moistures were observed, and in eastern Marlborough to Kaikoura where soil moisture levels were normal to above normal for this time of year.

Sunshine hours recorded between Te Kuiti and Palmerston North (including Taranaki) were below normal (75-89% of normal) for February while north of Auckland and the southern part of Wellington experienced near normal (90-109% of normal) sunshine hours. Many of the available, reporting stations in the South Island observed above normal (110-125% of normal) February sunshine hours, with well above normal (>125% of normal) hours recorded in Dunedin and Rangiora. Near normal sunshine was observed in northern Nelson and at locations in Dunedin, Christchurch, and parts of the West Coast.

Further Highlights:

• The highest temperature was 35.5°C, observed at Wairoa on 6 February.

• The lowest temperature was -0.5°C, observed at Hanmer Forest on 15 February.

• The highest 1-day rainfall was 149.4 mm, recorded at Milford Sound on 6 February.

• The highest wind gust was 178 km/hr, observed at Akitio on 13 February.

• Of the six main centres in February 2017, Dunedin was the sunniest and coldest, Tauranga was the wettest and warmest, Christchurch was the driest, and Hamilton was the least sunny.

• Of the available, regularly reporting sunshine observation sites, the sunniest four locations in 2017 (1 January – 28 February) were Gisborne (538.5 hours), Whakatane (529.8 hours), Blenheim (528.3 hours) and Lake Tekapo (522.6 hours)

Full summary Climate_Summary_February_2017_FINAL.docx

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