Current Climate - July 2013

July 2013 was characterised by much higher pressures than normal over and to the north, east, and west of New Zealand. Persistent lower pressures than normal were present well to the south of the country. This pressure pattern caused largely settled conditions over New Zealand for July, resulting in high mean temperatures for the time of year in much of the South Island and parts of the North Island, and dry conditions in the northern half of the North Island and eastern South Island. 

Rainfall

July was a very dry month for the upper half of the North Island (except for the Far North), as well as parts of coastal Manawatu, Nelson-Tasman, south Canterbury, and coastal Otago north of Dunedin. In these areas, well below normal rainfall for July occurred (less than 50 percent of normal July rainfall). Numerous locations had near-record-breaking low rainfall for July. In contrast, the southwest of the South Island, Ohakune, and southern Hawke's Bay received well above normal rainfall for July (more than 150 percent of normal July rainfall). Near normal rainfall was experienced elsewhere (within 20 percent of normal July rainfall). As at 1 August, most soils around the country were at normal soil moisture levels for the time of year. In Otago, soils were wetter than normal for the time of year, due to high rainfall in June.

Temperature

A very warm July was experienced in the South Island. Mean temperatures for July were well above average (more than 1.2°C above the July average) across most of the South Island, with many locations in Canterbury and Otago recording their highest July mean temperatures on record. Mean temperatures were also well above average in the south Taranaki, Manawatu-Wanganui, Wellington, and Wairarapa regions. Temperatures were above average (0.5 to 1.0°C above July average) in the northern South Island, as well as Hawke's Bay, parts of Taranaki, and the Central Plateau. North of Taupo, temperatures were generally near average (within 0.5°C of July average). The nation-wide average temperature in July 2013 was 9.0°C (1.2°C above the 1971-2000 July average) from NIWA's seven-station temperature series which begins in 1909. July 2013 recorded the 4th-highest July mean temperature on record for the seven-station series.

Sunshine

Sunshine hours were well above normal (more than 125 percent of July normal) for the eastern half of the North Island, north Canterbury, and Queenstown Lakes. Above normal sunshine (110-125 percent of normal July sunshine) was experienced for the remainder of the country, except for coastal southern Southland and Stewart Island (below normal sunshine, 75-90 percent of normal July sunshine), and coastal Manawatu-Wanganui and around Greymouth (near normal sunshine, within 10 percent of normal July sunshine). Of the available, regularly reporting sunshine observation sites, the sunniest four centres so far in 2013 (January to July) are: Whakatane (1630 hours), New Plymouth (1532), Tauranga (1468 hours), and Blenheim (1454 hours). 

Percentage of normal rainfall for July 2013.
End of month water balance in the pasture root zone for an average soil type where the available water capacity is taken to be 150 mm.
Departure from average air temperature for July 2013.