Coldest day on record
Cantabrians expecting to wake to another bone-chilling morning can at least take comfort from official figures showing that Wednesday was Christchurch's coldest day on record.
Further chaos and disruption is expected on roads this morning after temperatures dipped several degrees below freezing overnight.
The cold snap is a hangover from Wednesday's heavy snow, when the maximum temperature at Christchurch Airport in the official 24-hour period from 9am that day reached a pitiful 0.4 degrees Celsius.
The National Institute of Water and Atmospheric Research (Niwa) said that was the city's lowest day maximum in nearly 149 years of record-keeping.
Until Wednesday, the record was the daily maximum of 1.2C measured in the Christchurch Botanic Gardens on July 22, 1918.
While readings began in the gardens in 1863, figures have only been taken at the airport since 1954, where the previous coldest day maximum was 1.7C on August 28, 1992, during that year's big snow.
Early yesterday morning the mercury dipped to -5.8C at the airport, only slowly rising above freezing after 11am and peaking around 4.9C at 1pm before falling below freezing again by 5pm.
A slight thaw began in the afternoon where snow lay in direct sunlight but ice and snow were refreezing at dusk, prompting more warnings of treacherous conditions this morning for road users.
A spell of milder northwesterly winds later this morning is expected to push the temperature to about 10C for a time, allowing for more thawing, before another cold southwest wind change later in the afternoon.
Niwa senior climate scientist Georgina Griffiths said several other South Island spots on Wednesday had record-low maximum temperatures for June, including Lincoln, which reached only 0.7C, making it the coldest June day since records began there in 1881 and the second-coldest behind the 0.4C high on August 28, 1992.
Other June records included Greymouth, which only reached 5.2C, Blenheim Airport, up to 5.6C, and Arthur's Pass only reaching -1.2C, making it the fourth-coldest on record there in any month, although -4.1C on June 20, 1983 stands as the record.
Yesterday morning's icy roads caused at least 15 crashes in the city, while about 19 were reported in the snow on Wednesday.
Yvonne and Paul Devine were lucky to escape unharmed after their four-wheel-drive hit black ice on the Sefton to Rangiora Rd about noon yesterday. The vehicle flipped and ended up in a ditch, trapping the Waipara couple inside for a while.
Paul Devine said the road had appeared to be clear from snow and ice and because other traffic was passing through he thought driving would be fine.
"Next thing the car was starting to fishtail and it was just out of control. Once you get that little bit of movement, there's no stopping it."
They were both disoriented, but managed to free themselves.
"We're good as gold. I've got a headache and I'm a bit sore in the shoulders, but considering I'm 66 and just rolled a car over, I'm pretty good," he said. His wife Yvonne, 51, was not injured.
Senior Sergeant Steve King, of the Canterbury Highway Patrol, said none of yesterday's crashes were serious and no injuries had been reported.
Road conditions were challenging in places.
"Fortunately, most drivers have been doing the right thing – keeping speeds down, extending following distances and driving cautiously."
Traffic volumes were slightly lower than normal yesterday, which had helped keep crash rates down, King said.
However, the difficult conditions were not over yet, with melting snow expected to refreeze overnight, and non-essential travel should be avoided if the roads were icy.
Atomic Collision Centre co-owner Al Berry said his Sydenham workshop had dealt with nine more cars than usual since Wednesday.
Icy conditions meant some drivers were having trouble braking, but Berry said he thought most motorists were driving carefully.
Most of the cars in his workshop were in for minor repairs following nose-to-tail crashes, but three required repair jobs that would cost more than $5000 each, he said.
Advanced Panel and Paint Repair Shop manager Aaron Woolhouse said his workload had increased slightly.
"By the time they sort their insurance and that out, it'll probably be a couple of days [before they come in]," he said.