In Arthurs Pass, the main mountain route between Christchurch and the West Coast, the mercury plunged to -11.2C in the same period.
Those living in cracked, earthquake-damaged Christchurch homes were left struggling to heat their dwellings.
The weight of the snow dump, especially in Canterbury, brought trees down on powerlines and thousands of customers were without power.
But the Canterbury electricity lines company Orion said it expected to have fewer than 10 customers left in the dark by last night.
It expected that all its customers would have power today.
"The support and understanding of our community has been greatly appreciated over the past few days," said Orion chief executive Rob Jamieson.
"Whether it was clearing snow or supplying cups of tea, their help was appreciated."
Christchurch photographer John O'Malley was at his property in the remote central Canterbury village of Castle Hill on Tuesday when the snow starting falling.
It eventually got above his thighs in some places, he said.
He lost electricity about midday on Wednesday, and it did not come back on until about 5pm on Thursday.
He was fortunate to have a woodburner to heat his home, and stayed "well rugged up" when it plunged to -11C overnight.
The rest of the stranded village residents were also well stocked with the essentials, and some had generators to provide electricity, though there was some concern for pregnant women in the village.
"I quite liked being isolated like that," Mr O'Malley said. "It's nice to get away."
The freezing overnight temperatures turned snow to ice on Christchurch's roads and made driving conditions treacherous.
Dozens of minor accidents were reported, including one in which a four-wheel-drive vehicle flipped. The occupants were uninjured.
By late yesterday afternoon, St John Ambulance had taken 11 people to hospital with injuries from falls in snow or ice.
Many roads in and around Christchurch had to be closed during the week because of the dangerous icy conditions.
In some places, bus bus services had to be cancelled.