National Climate Centre Tuesday 1 August 2006
National Climate Summary – July 2006: A month of contrasts, warmer than average overall
- Rainfall: Very wet in Wairarapa, Wanganui, and Wellington (landslips and severe flooding in some areas); extremely dry
in parts of Northland, Auckland, and parts of Otago
- Temperature: Above average in the east of the North Island, Marlborough, Nelson, and Southern Lakes; below average in
Northland, inland South Canterbury, and North Otago
- Sunshine: Very sunny in the north and west of the North Island, as well as inland South Canterbury and coastal Otago
July was warmer than June (by 0.8 °C). This happens on average once in five years, and this year provided a reprieve
from the very cold start to winter. In fact, overall this July temperatures were slightly above average. The national
average temperature of 8.2 °C was 0.3 °C above the 1971-2000 normal. July 2006 temperatures were above average in the
east of the North Island, Marlborough, Nelson, and Southern Lakes, and below average in Northland, inland South
Canterbury, and North Otago.
An active low produced landslips, flooding and high rainfall in July in Wairarapa, and parts of Wanganui and Wellington
during the first week of the month. Rainfall for the month was more than twice normal in Wairarapa (in some places it
was the wettest July in more than 30 years), and more than one and a half times normal in King Country, Wanganui,
Hawke’s Bay, and Wellington (including the Kapiti coast). In contrast, July was rather settled in other areas with
rainfall totals a mere 25 percent (a quarter) or less of normal in parts of Northland, and North Otago, and 50 percent
(half) or less of normal in Auckland, Coromandel, Central and East Otago.
July was much sunnier than normal in the north and west of the North Island, as well as inland South Canterbury, and
coastal Otago.
More anticyclones (‘highs’) in the Australian Bight extended over New Zealand producing more south easterlies to the
north, with westerlies and southwesterlies to the south of the country.
Other Highlights:
- The highest temperature during July 2006 was 20.2 °C recorded at Whakatu, Hastings, on the 31st. The lowest air
temperature for the month was -12.2 °C recorded at Lake Tekapo on the 6th. Minimum air temperatures were –10 °C or lower
in parts of inland South Canterbury/North Otago on the 1st, 5th, 6th, and 7th of July.
- A wind gust of 148 km/h was recorded at Rock and Pillar, Otago on the 22nd, and 146 km/h at Mt. Kaukau, Wellington on
the 5th. Tornados destroyed property in the Waikato on the 12th.
- Severe flooding and landslips occurred after high rainfall from 4-6 July in the Wairarapa, Wanganui and Wellington
regions. 100 mm was reported within 24 hours in parts of South Wairarapa, where people had to be evacuated from their
homes. Martinborough was isolated by floodwaters, and surface flooding which also affected Greytown and Carterton. In
Wairarapa, more than 50 roads were closed due to flooding or landslips. The settlement of Mangamahu (northeast of
Wanganui) was isolated by the collapse of the Mangawhero river bridge. A house in Wanganui was struck by a landslide,
with two others later affected in Hunterville. On 21 July, an Eastbourne house became perched above a landslide.
- Snowfall closed the Desert Rd on the 6th, with many skiers stranded on Mt. Ruapehu. Showers of sleet and snow fell to
low levels in the lower North Island on the 21st, and settled in the Queenstown area; and closing Queenstown airport.
- Dunedin was the driest, Wellington the wettest, Auckland the sunniest, and Christchurch the coldest of the main
centres. Rainfall was well above average in Wellington and below average in all four other main centres. Temperatures
were above average in Wellington Dunedin, below average in Auckland, and near average in the other main centres.
Sunshine totals were above average in all five main centres.
Rainfall: Rainfall was more than 200 percent (twice) of normal in Wairarapa, and more than 150 percent (one and a half)
of normal in King Country, Wanganui, Hawke’s Bay, and Wellington (including the Kapiti coast). It was also wet in
Manawatu, and scattered areas of Canterbury. In contrast, July rainfall totals were 25 percent (a quarter) or less of
normal in parts of Northland, and North Otago, 50 percent (half) or less of normal in Auckland, Coromandel, Central and
East Otago. Rainfall was also below normal in Bay of Plenty, Buller, Westland, Marlborough, South Canterbury, and West
Otago.
Temperature: Mean temperatures were generally near average over the country. However, they were above average in the
east of the North Island, Marlborough, Nelson, and Southern Lakes. In contrast, temperatures were below average in
Northland, inland South Canterbury and North Otago.
Sunshine: Sunshine hours and/or solar radiation were at least 120 percent of normal in parts of Northland, Auckland,
Taranaki, Wellington, inland South Canterbury, and coastal Otago, and about 110 percent of normal in Waikato, Manawatu,
and Nelson.
RAINFALL: VERY WET IN WAIRARAPA, WANGANUI, AND WELLINGTON; EXTREMELY DRY IN PARTS OF NORTHLAND, AUCKLAND, AND PARTS OF
OTAGO
Rainfall was more than 200 percent (twice) of normal in Wairarapa, and more than 150 percent (one and a half) of normal
in King Country, Wanganui, Hawke’s Bay, and Wellington (including the Kapiti coast). It was also wet, with at least 125
percent (one and a quarter) of normal rainfall in Manawatu, and scattered areas of Canterbury. In contrast, June
rainfall totals were 25 percent (a quarter) or less of normal in parts of Northland, and North Otago, 50 percent (half)
or less of normal in Auckland, Coromandel, Central and East Otago, and 75 percent (three quarters) or less of normal in
Bay of Plenty, Buller, Westland, Marlborough, South Canterbury, and West Otago.
High July rainfall was recorded at:
Location July
Rainfall (mm) Percentage
of normal Year
Records began Comments
Taumarunui 285a 187 1914 Well above normal
East Taratahi 251b 268 1972 Highest
Martinborough 215 240 2001 Highest
Wellington, Kelburn 270 198 1862 Well above normal
Wellington Airport 206 182 1960 2nd highest
Waiouru MWD 194b 182 1950 2nd highest
Wanganui, Spriggens Pk. 176 200 1890 3rd highest
a Missing 5-days, b missing 1-day
Low July rainfall was recorded at:
Location July
Rainfall (mm) Percentage
of normal Year
Records began Comments
Kerikeri EWS 64 36 1982 2nd lowest
Kaikohe 50a 29 1986 2nd lowest
Whangarei Airport 33 21 1937 2nd lowest
Warkworth 57 31 1972 2nd lowest
Auckland, Mangere 46 33 1959 3rd lowest
Ranfurly 8 31 2001 2nd lowest
Middlemarch 5 14 2001 Lowest
Lauder 7 22 1986 Well below normal
a Missing 1-day
TEMPERATURE: ABOVE AVERAGE IN THE EAST OF THE NORTH ISLAND, MARLBOROUGH, NELSON, AND SOUTHERN LAKES; BELOW AVERAGE IN
NORTHLAND, INLAND SOUTH CANTERBURY, AND NORTH OTAGO
Mean temperatures were near average throughout much of New Zealand. However, they were at least 0.5 °C above average in
the east of the North Island, Marlborough, Nelson, and Southern Lakes. In contrast, temperatures were about 0.5 °C below
average in Northland, inland South Canterbury and North Otago.
High July mean temperatures were recorded at:
Location July
Mean air temperature (°C) Departure
from normal
(°C) Year
Records began Comments
Chatham Is. 9.4 +1.3 1957 2nd highest
SUNSHINE: WELL AVERAGE IN THE NORTH AND WEST OF THE NORTH ISLAND, AS WELL AS INLAND SOUTH CANTERBURY AND COASTAL OTAGO
Sunshine hours and/or solar radiation were at least 120 percent of normal in parts of Northland, Auckland, Taranaki,
Wellington, inland South Canterbury, and coastal Otago, about 110 percent of normal in Waikato, Manawatu, and Nelson,
and near normal in most other regions.
Well above average July sunshine hours were recorded at:
Location July
Sunshine (hours) Percentage
of normal Year
records began Comments
Dargaville 149 134 1943 3rd highest
Auckland, Mangere 159 122 1963 Well above average
New Plymouth 168 126 1973 Well above average
Stratford 153 127 1963 Well above average
Wellington, Kelburn 143 122 1928 Well above average
Lake Tekapo 138 127 1928 Well above average
Dunedin, Musselburgh 134 132 1948 Well above average
JULY’S CLIMATE IN THE FIVE MAIN CENTRES
Dunedin was the driest, Wellington the wettest, Auckland the sunniest, and Christchurch the coldest of the main centres.
Rainfall was well above average in Wellington and below average in the other main centres. Temperatures were above
average in Wellington and Dunedin, below average in Auckland, and near average in the other main centres. Sunshine
totals were above average in all five main centres.
Location July
Mean
Temp.
(°C) Dep.
from normal
(°C) July
rainfall
(mm) % of
Normal July
Sunshine
(hours) % of
Normal
Auckland 10.5 -0.4 Below average 75a 51 Below average 159 122 Well above average
Hamilton 8.7 -0.2 Near average 101 79 Below average 143 118 Above average
Wellington 9.2 +0.4 Above average 270 198 Well above average 143 122 Well above
average
Christchurch 6.0 +0.2 Near average 52b 73 Below average 137b 111 Above average
Dunedin 6.9
+0.3 Above average 29 44 Below average 134 132 Well above average
a Owairaka b Christchurch Airport
HIGHLIGHTS AND EXTREME EVENTS
Temperature
The highest temperature during July 2006 was 20.2 °C recorded at Whakatu, Hastings, on the 31st. The lowest air
temperature for the month was -12.2 °C recorded at Lake Tekapo on the 6th. Minimum air temperatures were –10 °C or lower
in parts of inland South Canterbury/North Otago on the 1st, 5th, 6th, and 7th of July.
High winds
A wind gust of 148 km/h from the southwest was recorded Rock and Pillar, Otago on the 22nd, and 146 km/h from the south
at Mt. Kaukau, Wellington on the 5th. On the 5th, gale force southerlies and 7 m swells resulted in the cancellation of
Cook Strait ferry sailings, and high winds damaged several roofs in Wellington. Twin tornados destroyed a garage and
trees in the Waikato, from Hamilton to Eureka, on the 12th.
High rainfall and floods
High rainfall totalling 100 to 160 mm or more over 3-days occurred throughout Wairarapa, Wanganui, and Wellington during
4-6 July. This resulted in high rivers and severe surface flooding throughout much of southern Wairarapa, along with
substantial landslips in parts of the Wanganui and Wellington regions. 100 mm was reported within 24 hours in parts of
South Wairarapa, where people had to be evacuated from their homes. Martinborough was isolated by the floodwaters, and
surface flooding also affected Greytown and Carterton. In Wairarapa, more than 50 roads were closed due to flooding or
landslips. In Wellington, a landslip occurred on SH2 affecting traffic between the city and the Hutt Valley. The
settlement of Mangamahu (northeast of Wanganui) was isolated by the collapse of the Mangawhero river bridge (damages
estimated at $10 million) following the high rainfall. 125 people were evacuated from Whangaehu, and Turakina. A house
in Wanganui was hit by a landslide, with two others later affected in Hunterville. In Taranaki SH45 was closed due to
surface flooding. On 21 July, an Eastbourne house became perched above a landslide, putting several others below it at
risk.
High rainfall during 4-6 July was measured at:
Location
Rainfall (mm)
4-6 July 2006
East Taratahi 155
Martinborough 122
Ngawi 158
Hawera 127
Wanganui Airport 101
Wellington, Kelburn 134
- Snowfall
Cold southerlies resulted in 10 cm of fresh snow lying at Tekapo on the 4th. Snowfall closed the North Island’s Desert
Rd on the 6th, with many skiers stranded on Mt. Ruapehu. Showers of sleet and snow fell to low levels in the lower North
Island on the 21st, and chains were required due to heavy snowfall in the Queenstown area, which closed Queenstown
airport.
ENDS