Current Climate - June 2013

June 2013 was characterised by lower pressures than normal across New Zealand and to the north and northeast of the country, with persistent high pressure centres south and southeast of Tasmania.  This resulted in an anomalous east-southeasterly flow over the South Island, which contributed to well above normal rainfall totals recorded throughout areas to the east of the Southern Alps.  Of particular note was the storm of 19-21 June, which brought the strongest sustained 10-minute winds that Wellington airport has seen since 1985.  These strong winds resulted in widespread damage to infrastructure and vegetation in Wellington, and a loss of power for up to 30,000 homes.  In addition, cold south-southeasterly winds associated with the storm resulted in a significant snowfall event across the South Island.  Areas of the Mackenzie Country and the Maniototo bore the brunt of snowfalls, with unofficial reports of more than half a metre of snow there.  Most South Island ski areas received in excess of one metre of new snow by the end of the storm, with Mt Hutt inundated by an estimated new snowfall total approaching three metres.

Rainfall

June was a relatively wet month for eastern and northern parts of the South Island, as well as southern and south-eastern parts of the North Island.  Locations throughout Central Otago recorded their wettest June since respective records began, as did Timaru and Lincoln in Canterbury.  Areas of North Otago, South and mid-Canterbury received more than 400 percent of June normal rainfall.  More than 200 percent of June normal rainfall was recorded in parts of South Otago, Central Otago, Mackenzie Country, North Canterbury and Marlborough.  Similarly, Nelson, Wellington and the Wairarapa Coast experienced well above normal rainfall for the month (greater than 150 percent of June normal rainfall), and above normal rainfall (between 120 and 150 percent of June normal rainfall) was recorded in parts of northern Southland and Waikato.  In contrast, rainfall was below normal (50 to 79 percent of June normal rainfall) in parts of Fiordland, West Coast, Manawatu, inland Taranaki and eastern Bay of Plenty.  As at 1 July, soil moisture levels across the majority of New Zealand had reached field capacity.  Areas of Otago, Canterbury and Marlborough were wetter than normal for the time of year, and were also observing a soil water surplus.  Below normal soil moisture deficit levels were observed in northern parts of the Coromandel Peninsula and Great Barrier Island.

Temperature

Mean temperatures for June were above average (0.5 to 1.2°C above the June average) across areas of southern and western Southland, Fiordland, Westland, Manawatu, Hawke’s Bay, Gisborne and Bay of Plenty.  June temperatures throughout inland Canterbury were below average (0.5 to 1.2°C below the June average).  In general, June temperatures were near average throughout the remainder of the country (within 0.5°C of June average).  The interim nation-wide average temperature in June 2013, using only six stations (most of the month was missing for Nelson owing to vandalism at the site) from NIWA’s seven-station temperature series which begins in 1909 is 8.9°C, an anomaly of +0.4°C. 

Sunshine

Sunshine hours for June were above normal (110 to 124 percent of June normal) for northern Manawatu and western Southland. Sunshine was well above normal (more than 125 percent of June normal) in Fiordland and southern Westland. Sunshine hours were below normal (75-90 percent of June normal) throughout areas of Otago, Marlborough, Tasman, Nelson, Wellington and coastal Taranaki.  Of the available, regularly reporting sunshine observation sites, the sunniest four centres so far in 2013 (January to June) are: Whakatane (1435 hours), New Plymouth (1390 hours), Blenheim (1273 hours) and Paraparaumu (1261 hours).