National Climate Summary – August 2005

NATIONAL CLIMATE CENTRE THURSDAY 1 SEPTEMBER 2005

National Climate Summary – August 2005

- 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

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

- 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.

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.

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 of average in Southland and Fiordland.

BELOW AVERAGE RAINFALL IN MANY REGIONS,
ESPECIALLY IN THE EAST, FROM HAWKE’S BAY TO OTAGO

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, and 75 percent or less (three quarters) of normal in many other regions. Fiordland was the only region with above average rainfall (at least YY percent of normal). Rainfall was near normal in Westland, the Southern Lakes, and Gisborne and western Bay of Plenty.

Near or record low August rainfall was recorded at:

Location August Rainfall (mm) Percentage of normal Year records began Comments
Dargaville 31 27 1943 Lowest
Whangarei Airport 54 37 1937 2nd lowest
Warkworth 43 27 1972 2nd lowest
Auckland, Henderson 45 28 1986 Lowest
Auckland, Owairaka 46 38 1949 2nd lowest
Auckland, Mangere 35 30 1959 Lowest
Auckland Airport 38 35 1962 2nd lowest
Pukekohe 37 34 1970 Lowest
New Plymouth Airport 52 41 1944 Lowest
Waione 25 21 1992 Lowest
East Taratahi 19 21 1972 Lowest
Martinborough 19 23 2001 Lowest
Ngawi 26 22 1989 2nd lowest
Whakatu 16 28 1983 Equal lowest
Paraparaumu Airport 23 26 1945 2nd lowest
Wellington, Kelburn 30 24 1862 2nd equal lowest
Wellington Airport 35 36 1960 Equal lowest
Wallaceville 18 14 1924 Lowest
Farewell Spit 35 25 1874 Well below normal
Stephens Island 20 23 1894 3rd lowest
Blenheim Research 15 20 1985 Lowest
Blenheim Airport 22 31 1941 3rd lowest
Awatere Valley 13 18 2001 Lowest
Cape Campbell 10 14 1874 Well below normal
Hanmer Forest 12 10 1905 Lowest
Kaikoura 24 31 1949 Well below normal
Rangiora 8 13 1999 Lowest
Darfield 10 11 1920 3rd equal lowest
Christchurch Airport 13 20 1944 Well below normal
Christchurch Gardens 11 16 1864 3rd lowest
Le Bons Bay 11 9 1989 Lowest
Timaru Airport 11 24 1957 Well below normal
Oamaru Airport 8 18 1941 Well below normal
Middlemarch 10 34 1916 Well below normal
Dunedin Airport 10 19 1963 Lowest
Musselburgh 10 15 1918 2nd lowest
Nugget Point 19 30 1930 3rd equal lowest

ABOVE AVERAGE TEMPERATURES OVER THE SOUTH ISLAND, AVERAGE OR ABOVE OVER THE NORTH ISLAND

Mean temperatures about 1.5 °C above average in parts of Wellington, Marlborough, Canterbury, West Otago, and Southland, 1.0 °C above average in Manawatu, Wairarapa, and Nelson, and about 0.5 °C above average in Auckland, Hawke’s Bay, and the remainder of Otago. They were near average elsewhere.

Near or record high August mean air temperatures were recorded at:

Location Mean temperature Departure from average (°C) RecordsBegan Comments
Motu 8.1 +2.5 1992 Highest
Mt. Ruapehu, The Chateau 4.8 +1.6 1932 2nd highest
Wellington, Kelburn 10.7 +1.5 1862 2nd highest
Wellington Airport 11.3 +1.4 1962 2nd equal highest
Farewell Spit 11.2 +1.5 1971 3rd equal highest
Puysegur Point 10.0 +1.6 1980 Highest
Blenheim Research 10.2 +1.6 1985 Highest
Hanmer Forest 7.7 +2.1 1906 2nd highest
Kaikoura 10.2 +1.7 1964 2nd equal highest
Winchmore 8.5 +1.7 1950 3rd highest
Lincoln 9.3 +2.1 1881 2nd highest
Dunedin, Musselburgh 8.8 +1.3 1947 2nd highest
Manapouri Airport 6.7 +1.9 1992 Highest
Queenstown 7.3 +1.5 1872 2nd highest
Lauder 6.5 +1.8 1981 2nd highest
Gore 7.4 +1.5 1986 Highest
Invercargill Airport 7.9 +1.5 1948 Highest
Tiwai Point 8.7 +1.5 1970 Highest
Chatham Islands 9.5 +1.0 1957 Equal highest

EXTREMELY SUNNY THROUGHOUT THE NORTH ISLAND

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, with new records established in Auckland, Hamilton, Tauranga, Taumarunui, New Plymouth, Stratford, and Palmerston North. In contrast, it was cloudier than normal in Southland and Fiordland.

Near record high August sunshine hours were recorded at:
Location August sunshine (hours) Percentage of normal Year Records began Comments
Kaitaia 191 125 1985 3rd highest
Dargaville 180 134 1943 2nd highest
Auckland 204 144 1910 Highest
Tauranga Airport 216 128 1933 Highest
Hamilton, Ruakura 195 141 1936 Highest
Taumarunui 151 141 1947 Highest
New Plymouth 229 149 1915 Highest
Gisborne Airport 209 135 1906 Highest
Palmerston North 199 171 1931 Highest
Paraparaumu Aiprort 188 129 1953 3rd highest
Wellington, Kelburn 194 143 1928 2nd highest 204, highest since 1935
Stratford 193 147 1963 Highest
Blenheim 221 124 1930 2nd highest
Lake Tekapo 197 131 1928 2nd equal highest
Dunedin, Musselburgh 156 137 1948 3rd highest

AUGUST’S CLIMATE IN THE FOUR MAIN CENTRES

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 or record August sunshine hours in Auckland, Wellington, and Dunedin.

Location AugustMean Temp. (°C) Dep. from normal (°C) August rainfall (mm) % of normal August Sunshine (hours) % of Normal
Auckland 11.9a +0.4 Above average 45b 37 2nd lowest 204a 144 Record high
Wellington 10.7 +1.5 2nd highest 30 24 2nd equal lowest 194 143 2nd highest
Christchurch 8.2c +1.1 Above average 13c 20 Well below average 181 123 Well above Average
Dunedin 8.9 +1.3 Equal highest 10 15 Well below average 156 137 Well above average

a Mangere b Mt Albert c Christchurch Airport

HIGHLIGHTS AND EXTREME EVENTS

- Temperature

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 both exceeding the previous all-time New Zealand maximum temperature record for August. These and other near or record high August maximum temperatures are listed below. Maximum temperatures reached at least 20.0 °C somewhere in Canterbury every day from 19 through 23 August.

Near or record high August maximum air temperatures were recorded at:

Location Maximum temperature °C Date of occurrence Year Records began Comments
Amberley 25.4 31st 1973 Highest *New New Zealand record
Hanmer Forest 25.1 30th 1906 Highest *Exceeded previous New Zealand record
Waipara 23.8 31st 1973 Highest
Ranfurly 23.0 31st 1975 Highest
Lauder 22.2 31st 1987 Highest
Alexandra 22.0 29th & 30th 1993 Highest
East Taratahi 21.9 31st 1972 Highest
Ngawi/Cape Palliser 21.8 31st 1972 Highest
Waione 21.6 30th 1993 Highest
Tara Hills 21.6 31st 1950 Highest
Clyde 21.6 31st 1983 Highest
Dunedin Airport 21.1 21st 1963 3rd highest
Blenheim Airport 21.0 30th 1941 Highest
Motu 20.9 31st 1991 Highest
Mt Cook Village 20.9 31st 1931 Highest

The lowest temperature for the month was -7.1°C, recorded at Lake Tekapo on the 11th.

- High winds

The highest wind gust for the month was 154 km/h from the northwest, recorded at South West Cape on the 19th.

ENDS

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