July 2005

Temperature: Third warmest July on record

Rainfall: Below average in many eastern districts from Wairarapa to Otago, above average in the north of the North Island

Sunshine: Well above average in inland south Canterbury and coastal Otago, below average in Taranaki, Nelson, and Marlborough

July, for many, was very much warmer, and windier than normal. The national average temperature of 9.1 °C was 1.2 °C above normal, and the third highest for July in reliable records dating back to the mid 1860s. Only July 1998 (9.6 °C) and July 2000 (9.3 °C) were warmer. There were only about half the average number of days with screen (air) frost in July in many North Island and most low lying/coastal South Island locations. Frostiness was also less frequent in inland South Island areas. Rainfall was well below normal in Wairarapa, and in much of Canterbury and Otago, with significant soil moisture deficits for the time of year in North and Central Otago. Rainfall was above normal in much of Northland, parts of Bay of Plenty, and along the Kaikoura coast. Sunshine hours were well above average in inland south Canterbury, and coastal Otago. However, they were well below average in Taranaki. During July, anticyclones ('highs') were often centred northeast of the North Island, while low pressures associated with depressions prevailed well south of the country. This pattern resulted in more frequent westerlies and north westerlies, especially over southern New Zealand. July’s warmth was due to more wind (frequent northwesterlies), and generally cloudier than usual skies (especially overnight) for the time of year.

Other Highlights

  • High rainfall totalling 130 – 215 mm occurred over 4-6 July in inland and eastern parts of Northland with some flooding. High rainfall totalling 160 – 170 mm occurred in the high country of southern Coromandel and western Bay of Plenty, accompanied by severe electrical storms from Northland to Thames. Isolated, but heavy rainfall (about 100 mm) occurred on 19 July in the Kakanui Range (north Otago) causing the Kakanui River to reach its highest flood level since January 2002.
  • High winds over 12/13 July damaged power lines on the Coromandel Peninsula over the night, leaving thousands of residents without electricity.
  • The highest temperature during July 2005 was 22.0°C recorded in Hastings on the 15th. The lowest temperature for the month was -8.5°C, recorded at Middlemarch on the 15th.
  • Of the four main centres Dunedin was the driest and sunniest, and Auckland the warmest. Rainfall was above average in Auckland, but below average in the three other main centres. Temperatures were much above average in all four centres. Sunshine hours were well above average in Dunedin, and below average in Auckland, Wellington, and Christchurch.

Rainfall

Rainfall was less than 50 percent (half) of normal rainfall in parts of Canterbury and Otago, and about 50 percent of normal in Wairarapa. Totals were also below normal around Rotorua. Rainfall was 150-175 percent of normal in much of Northland, parts of Bay of Plenty, and along the Kaikoura coast.

Sunshine

Sunshine hours were at least 120 percent of average in inland south Canterbury, and coastal Otago, and more than 110 percent of average in Southland. However, they were less than 80 percent of average in Taranaki, and less than 90 percent of average in Nelson, and Marlborough.

Temperature

Mean temperatures were 2°C above average in parts of Buller, Marlborough, and Central Otago, 1.5 °C above average throughout the remainder of the South Island; and about 1.0 °C above average in the North Island.

Full report

Full details of July 2005 summary.

For further information, please contact:

Dr Jim Salinger – Principal Scientist, Climate
NIWA National Climate Centre – Auckland
Phone +64 9 375 2053
[email protected]

Stuart Burgess – Climatologist
NIWA National Climate Centre – Wellington
Phone +64 4 386 0569
[email protected]

Geoff Baird – Communications Manager
Phone +64 4 386 0543
[email protected]

Acknowledgement of NIWA as the source is required.