It was not yet known whether the cold conditions were a factor in the crash.
The two-car crash happened at 6.15am and Inspector Dave Gaskin said a 55-year-old Timaru woman died at the scene.
The male driver of the other car was taken to hospital but has since been discharged.
The death has been referred to the Coroner and police said no further details of the deceased female will be released until the process to inform next of kin has been completed.
Rangitata resident John Hands said the roads were not as icy as yesterday but there was still a strong frost on the ground.
Snow had fallen down to about 400m, he said.
"It's not as bad as it was yesterday but there's a good frost here at the moment, ice on the water troughs and all that," Mr Hands said.
SH1 is closed north of Orari at Looker Rd and diversions, at Edgar Rd and Old Main South Rd, are likely to be in place until the early afternoon.
Before 7am, a man was thrown from his car in a serious crash on Alfriston-Ardmore Rd in South Auckland.
The man was taken to Middlemore Hospital in a critical condition, police said.
Alfriston-Ardmore Rd, Alfriston-Brookby Rd and Clevedon-Takanini Rd were closed from 7am as a scene examination took place.
Another two Auckland crashes and one in Wellington caused headaches for commuters this morning.
A collision between a motorcycle and a utility vehicle closed two westbound lanes of Mount Albert Rd in Royal Oak.
The motorcyclist was taken to hospital in a moderate condition.
It followed a two-car collision on the city-side of the Harbour Bridge about 6.45am.
The Wellington crash on SH1 north of Paekakariki is still causing delays for motorists
The New Zealand Transport Agency was warning drivers to take extreme car in the South Island -- with the Northern Motorway out of Dunedin reopened about 8.45am after initially being closed due to snow and ice.
Black ice was expected overnight and in shady patches early this morning following snow and sleet in the South Island, NZTA journey manager Lee Wright said.
Eleven people were injured on Otago roads during the weekend after ice and snow created treacherous driving conditions.
It was also treacherous around Mt Ruapehu, with several minor crashes reported in Waiouru on Sunday and early this morning.
Drivers were stranded at the Turoa ski field when a storm came through on Sunday.
One man was hit by a car in the carpark at 5.30pm due to the icy conditions.
