October 2010: Spectacularly sunny and very dry in most areas

 

National Climate Summary – October 2010: Spectacularly sunny and very dry in most areas 

• Rainfall: Extremely dry in Nelson and northern and western parts of the North Island.  Very wet in Gisborne and Hawkes Bay.  Rather dry elsewhere.
• Sunshine: Spectacularly sunny, with many records broken.
• Temperatures: Near average temperatures for many regions. Cooler than usual for the east coast of the North Island, as well as parts of Buller, The Sounds, and near Kaitaia. Warmer than average in the southwest South Island. 

 

 

Overall, October 2010 was extremely sunny and very dry in most regions.  More anticyclones (‘highs’) covered New Zealand than is typical for the time of year, resulting in a rather settled climate during the month.  The exceptions were an extremely cold southerly event which affected the country on the 11th and 12th, and a subsequent wet period for the east coast of the North Island between the 13th and 15th.   

October rainfall was more than double normal (at least 200 percent) in Gisborne and Hawkes Bay.  But for the remainder of the country, it was very dry, reflecting the prevalence of anticyclones.  Rainfalls were well below average (less than 40 percent of normal) across much of the North Island (excluding the east coast).  It was the driest October in Nelson since records began in 1941, with less than 10 percent of normal rainfall.  Elsewhere in the South Island it was rather dry, with rainfall between 50 and 80 percent of normal, except for Southland, which experienced closer to normal rainfall.  By the end of October, larger than normal soil moisture deficits had developed in much of Northland, coastal Nelson, mid Canterbury, and North Otago. 

Sunshine totals were well above average (more than 125 percent of normal) across most of the South Island, and the north and west of the North Island.  Many October sunshine records were broken.  It was the sunniest October since records began at Kaitaia, Te Kuiti, Taumarunui, Takaka and Nelson, Timaru, Dunedin, and Balclutha.  Sunshine totals were also slightly up for the eastern North Island (with sunshine totals between 100 and 115 percent of normal), despite the much higher than normal October rainfall there.     

Extremely cold temperatures affected the country on the 11th and 12th, followed by unusually warm spells on the 16th and 30th.  Even with the extreme swings in temperature, monthly mean temperatures were near average (within 0.5°C of average) for much of the country.  The exceptions were above average temperatures recorded in the southwest of the South Island (between 0.5°C and 1.2°C above average), and below average temperatures (between 0.5°C and 1.2°C below average) in Gisborne, Hawkes Bay, the Wairarapa, parts of Buller, the Sounds, and around Kaitaia.  The New Zealand national average temperature was 11.7°C (0.5°C below the 1971–2000 October average). 

Further Highlights:

• The highest temperature recorded was 28.4°C, recorded at Waiau on the 16th.
• The lowest temperature recorded was -4.4°C, recorded at Hanmer on the 12th.
• The highest 1-day rainfall was 151 mm recorded at Patutahi (Gisborne) on the 13th (a new record there).
• The highest wind gust was 159 km/hr, recorded at Puysegur Point on the 16th (a near-record there).
• Of the six main centres, Tauranga was the warmest, Wellington the wettest, and Christchurch the coolest and driest.  All of the main centres except Wellington were extremely sunny, but Tauranga and Christchurch topped the group, recording 246 and 245 hours of bright sunshine, respectively.

 

 

Rainfall: extremely dry in nelson, and northern and western parts of the north island.  very wet in gisborne and hawkes bay.  Rather dry elsewhere. 

October rainfall was more than double normal (at least 200 percent) in Gisborne and Hawkes Bay.  But for the remainder of the country, it was a very dry month, reflecting the prevalence of anticyclones.   

Rainfall totals were well below average (less than 40 percent of normal) across much of the North Island (excluding the east coast).  It was the driest October for Nelson since records began in 1941, with less than 10 percent of normal rainfall reported.  Elsewhere in the South Island, rainfall was below normal (between 50 and 80 percent of normal), except for Southland, which experienced closer to normal rainfall (between 80 and 120 percent of normal).   

By the end of October, larger than normal soil moisture deficits had developed in much of Northland, coastal Nelson, mid Canterbury, and North Otago. 

Record or near-record October rainfall totals were recorded at: 

 

 
 

 

 

SUNShine:  SPECTACULARLY SUNNY OVER much of THE SOUTH ISLAND AND north and WEST OF NORTH ISLAND.  MANY RECORDS BROKEN.   

Sunshine totals were well above average (more than 125 percent of normal) across most of the South Island, and the north and west of the North Island.  Many October sunshine records were broken.  It was the sunniest October since records began at Kaitaia, Te Kuiti, Taumarunui, Takaka and Nelson, Timaru, Dunedin, and Balclutha.  Sunshine totals were also slightly up for the eastern North Island (with sunshine totals between 100 and 115 percent of normal), despite the much higher than normal October rainfall there.   

 

Record or near-record October sunshine hours were recorded at: 

 

 

 

TEMPERATURES:  near average temperatures for many regions.  cooler than usual for the east of the north island as well as parts of buller, the sounds, and around kaitaia. warmer than average in the southwest south island. 

Extremely cold temperatures affected the country on the 11th and 12th, followed by unusually warm spells on the 16th and 30th.  Even with the extreme swings in temperature, monthly mean temperatures were near average (within 0.5°C of average) for much of the country.  The exceptions were above average mean temperatures for the southwest of the South Island (between 0.5°C and 1.2°C above average), and below average mean temperatures (between 0.5°C and 1.2°C below average) in Gisborne, Hawkes Bay, the Wairarapa, parts of Buller, The Sounds and around Kaitaia.  The New Zealand national average temperature was 11.7°C (0.5°C below the 1971–2000 October average)1. 

 

Record or near-record October mean minimum daily air temperatures were recorded at: 

 

 

 

Record or near-record October mean maximum daily air temperatures were recorded at: 

 

 

 

OCTOBER CLIMATE IN THE SIX MAIN CENTRES  

Of the six main centres in October 2010, Tauranga was the warmest, Wellington the wettest, and Christchurch the coolest and driest.  All of the main centres except Wellington were extremely sunny, but Tauranga and Christchurch topped the group, recording 246 and 245 hours of bright sunshine during the month, respectively.  

October 2010 main centre climate statistics: 

 

a Mangere      b Tauranga Airport   c Hamilton Airport     d Kelburn     e Christchurch Airport    f Musselburgh g Ruakura   
 
 

HIGHLIGHTS AND EXTREME EVENTS 

• Heavy rain and slips

 

 

The only significant rainfall event in the month affected the east coast of the North Island during the period October 13th - 15th. The highest 1-day rainfall in October 2010 was 151.4 mm, recorded at Patutahi (Gisborne) on the 13th (a new October record there). 

On 13 October, heavy rain caused slips and flooding, closing SH2 between Napier and Wairoa, SH35 north of Tolaga Bay, and many minor roads in the area. Dozens of homes were left without power, rural schools were closed, and many families were evacuated from Tolaga Bay. 

On 14 October, a series of slips overnight, from the Matahorua Gorge to Tangoio, just north of Napier, made SH2 impassable. About 20 cars were trapped overnight between two slips. North of Gisborne, flooding reduced SH2 to one lane north of Te Karaka, and SH35 to one lane between Gisborne and Ruatoria. Firefighters had to pump out flooded marquees at the Gisborne showgrounds before the annual A&P show. In Napier, flooding was reported at the EIT campus. Wairoa airport was closed, and so patients had to be driven south on SH2 to Hawke's Bay Hospital. In northern Wairarapa, a huge slip blocked the road from Pahiatua to Makuri and Pongoroa.  On 15 October, more than 20 motorists, some towing horses, were trapped between a slip at Otoko Hill and a washed-out bridge on SH2. In Hawkes Bay, Eskdale residents were isolated by flood waters. 

Record or near record high extreme 1-day rainfall totals were recorded at:  

 

*The Patutahi daily rainfall record spans 1890-1958, and 2003-2010. 

• Temperature

 

 

October 2010 was characterised by an extremely cold southerly event on the 11th, which brought record or near-record low temperatures for October to many North Island locations, and some South Island areas, during the subsequent 24 hours.  The lowest temperature recorded in October 2010 was -4.4°C, recorded at Hanmer on the 12th.  In contrast, the second half of October brought several periods of unusually warm weather, with notably warm temperatures occurring on the 16th, and 30th.  The highest temperature recorded in October 2010 was 28.4°C, recorded at Waiau on the 16th. 

Record or near-record daily minimum air temperatures were recorded at:

 

 

 

Record or near-record daily maximum air temperatures were recorded at:

 

 
 

 

• High winds

 

 

The highest gust observed during October 2010 was 159 km/hr, recorded at Puysegur Point on the 16th (a near-record there). 

On 10 October, high winds between Alexandra and Roxburgh blew over a campervan. Several road signs in the area were also damaged by the wind.  

On 11 October, strong winds disrupted flights in and out of New Plymouth Airport, blew down trees and power lines in Inglewood and Taumarunui, and brought down branches near Hunterville. 

On 13 October, high winds made driving difficult for the Energywise Rally drivers who were trying to conserve fuel in the four-day rally from Auckland to Wellington, and in Karapiro, the restaurant marquee under construction for the athletes at the World Rowing Championships was blown inside out.  

On 16 October, extremely strong winds fanned a controlled burn on Lake Ohau Station, carrying ash and sparks about 500 m. The fire was contained by about 6 pm. 

On 17 October, gale-force winds in Hataitai, Wellington damaged a church steeple, which had be brought down. At Mangamingi near Eltham, a 25-m gum tree was uprooted. Around Wanaka, the high winds lifted roofs and tossed trampolines in Cardrona, toppled a trailer home at Lake Hawea, and brought down trees at Hawea Flat. At Mount Cook village, wind tore a wall off a building, sucked windows out of vehicles, and uprooted trees.  

On 19 October, high winds caused problems for high sided vehicles on SH1 from Waihola to Gore, SH8 from Raes Junction to the intersection with SH1, SH90 from Raes Junction to McNabb, and SH87 from Outram to Kyeburn. 

Near-record high extreme wind gusts for October were recorded at:  

 

 
 

 

• Snow and ice

 

 

On 10 October, snow fell in Southland, Otago and South Canterbury. 

On 11 October, snow closed the Desert Road section of SH1 between Rangipo and Waiouru. Snow was also reported on the Mamaku Ranges near Rotorua, on Mount Pirongia near Te Awamutu, and to low levels on Mount Taranaki. On 11 October, the planned Ranfurly Shield parade through Christchurch was cancelled as it was too cold. 

On 20 October, chains were required on SH94, Te Anau to Milford Sound, after overnight snow. 

• Lightning and hail

 

 

On 11 October, a heavy hail storm hit Tariki, and power was lost for a few hours at Te Kiri, near Opunake. Hail also affected Wellington City in the early morning.  

On 18 October, hail fell on Canterbury from Rakaia Gorge to Pegasus Bay.