Current Climate - July 2014

July 2014 was characterised by lower pressures than normal over New Zealand with well below normal pressures to the south and east of the country.

This pressure pattern resulted in an anomalous south to south-easterly flow across New Zealand. This is in contrast to last month (June 2014), when a northerly flow anomaly contributed to New Zealand observing its warmest June on record.

Rainfall

There was quite a contrast in rainfall observed across the country in July. Heavy downpours in Northland meant that the region received well above normal rainfall (>149%) with some stations in the region recording levels double of what is expected in July. Similarly, the south-east coast of Southland also had a wet mid-winter with well above normal rainfall recorded.  The remainder of the country experienced a relatively dry July. Below normal rainfall (50-79%) characterised much of Auckland, the south-eastern coast of the North Island and the western coast of the South Island. The Bay of Plenty, Gisborne, Taranaki, Manawatu-Whanganui, Nelson-Marlborough and Canterbury regions were even drier with less than 40% of normal July rainfall recorded.

Temperature

After a record breaking warm June, temperatures remained above average (0.51 to 1.20°C) in many parts of the country at the start of July.  This warmth was short lived and a switch to a predominantly south-easterly flow brought cooler conditions to New Zealand which are more typical for this time of year.  As a whole, mean temperatures for most parts of the country were in the near average range (within 0.5°C of average) for the month of July. Pockets of below average temperature (-1.20 to -0.51°C) were recorded in the districts of Waitomo and Ruapehu, whereas above average (0.51 to 1.20°C) temperatures were observed in southern Canterbury and Otago. The last day of July was particularly warm for eastern parts of the South Island where the combination of a north-westerly flow and the foehn effect brought the region some mid-winter warmth and set July daily maximum temperature records in several locations. The nation-wide average temperature in July 2014 was 8.2°C (0.3°C above the 1971-2000 July average from NIWA’s seven station temperature series which begins in 1909)

Sunshine

It was an unusually sunny mid-winter winter in the North Island, with well above normal (>125%) or above normal (110-125%) sunshine recorded. The regions of Waikato and Bay of Plenty were particularly sunny with sunshine hours in excess of 125% recorded. Despite the rain in Northland, the region experienced many sunny days with above normal sunshine hours recorded for July as a whole. The South Island was also sunny for the most part with above normal sunshine (110-125%) hours recorded in the regions of Nelson, Marlborough, the West Coast, Otago and parts of Canterbury. Banks Peninsula, coastal Otago, the south coast of Southland and the district of Buller were not as bright and received below normal sunshine (75-89%).

Soil Moisture

Despite a relatively dry month for many parts of the country, soil moisture levels as of 1 August were normal for this time of year. Timaru was the only location experiencing below normal soil moisture levels which coincides with the low rainfall experienced in this area during July. Low soil moisture levels were present for much of the Hawkes Bay during early July but were able to recharge throughout the second half of the month and are now in the near normal range.