August 2005

Temperature: One of the warmest Augusts on record; record breaking temperature extremes
Rainfall: Below average in many regions - especially in the east from Hawke’s Bay to Otago; above average in the far southwest of the South Island
Sunshine: Extremely sunny in the North Island, above average over much of the South Island
August was much drier, warmer, and much sunnier than normal over most of New Zealand. Many northern and eastern regions of the country recorded less than 50 percent (half) of their normal rainfall.

Temperature: One of the warmest Augusts on record; record breaking temperature extremes

Rainfall: Below average in many regions - especially in the east from Hawke’s Bay to Otago; above average in the far southwest of the South Island

Sunshine: Extremely sunny in the North Island, above average over much of the South Island

August was much drier, warmer, and much sunnier than normal over most of New Zealand. Many northern and eastern regions of the country recorded less than 50 percent (half) of their normal rainfall. This was especially noticeable in the east between Wairarapa and Otago, with record low totals in many places of between about 10 and 15 mm. The weather was also rather settled for the time of year, Hanmer Forest and Timaru Airport recording at least 1.0 mm of rain on only two days during the month. The lack of rainfall has resulted in significant soil moisture deficits for the time of year in northern and eastern Otago and South Canterbury. The month was much warmer than normal with the national average temperature of 9.8 °C being 1.1 °C above normal: the fourth highest for August in reliable records dating back to the mid 1860s. Only August 1893 and 1967 (both 9.9 °C), and August 1987 (10.0 °C) were warmer. Sunshine hours were very much above average throughout the North Island, especially in the west between Auckland and Wellington, and in coastal Otago, where many locations (including Auckland, Hamilton, Tauranga, Taumarunui, Gisborne, New Plymouth, Stratford, and Palmerston North) established new record high totals for August, equivalent to what is normally experienced during October. More anticyclones occurred to the east of the South Island extending west over central New Zealand. This produced more frequent northwesterlies over much of the South Island. The anticyclones combined with the frequent north westerlies, along with the wind and extra sunshine, resulted in August’s overall warmth and dryness.

Other Highlights

  • The highest temperatures during August 2005 were 25.1 °C recorded at Hanmer Forest on the 30th, and 25.4 °C recorded in Amberley on the 31st. These both exceeded the previous all-time New Zealand maximum temperature record for August.
  • The lowest temperature for the month was -7.1 °C, recorded at Lake Tekapo on the 11th.
  • The highest wind gust for the month was 154 km/h from the northwest, recorded at South West Cape on the 19th.
  • Of the four main centres Dunedin was the driest, while Auckland was the warmest. Rainfall was well below average in all four main centres. Temperatures were above average in all four centres, with near records in Wellington and Dunedin. It was very sunny in all four centres, with near record August sunshine hours in Auckland, Wellington, and Dunedin.

Rainfall

Rainfall was less than 25 percent (quarter) of normal rainfall in much of Canterbury, coastal Otago, Wairarapa and Wellington, less than 50 percent (half) of normal in much of Northland, Auckland, Wanganui, Manawatu, Hawke’s Bay, Marlborough, and Nelson. Rainfall was also below average in many other regions. Fiordland was the only region with above average rainfall.

Sunshine

Sunshine hours were at least 125 percent of average throughout the whole of the North Island and in coastal Otago, and more than 110 percent of average over much of the South Island. Sunshine hours were below average in Southland and Fiordland.

Temperature

Mean temperatures about 1.5 C above average in parts of Wellington, Marlborough, Canterbury, West Otago, and Southland, and 1.0 °C above average in Manawatu, Wairarapa, and Nelson. Temperatures were also above average in Auckland, Hawke’s Bay, and the remainder of Otago.

Full report

Full details of August 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.

File attachments

In this issue