Teams were working in a challenging live slip environment from dawn to dusk to open that part of the state highway, as they were aware it was is critical to Northland, Ms Hori-Hoult said.
There are two alternative routes available for all traffic travelling between Northland and Auckland. People driving north are advised to use SH12 and the Paparoa-Oakleigh Road. Those heading south can travel through Waipu and Mangawhai.
The detours will add between 30 and 40 minutes to travel times.
Meanwhile, Mt Ruapehu has benefited more than other major skifields from an icy blast moving up the country.
MetService meteorologist John Law said there was a little more snow on the Rimutaka Hill Road throughout the day, however it was now easing off.
A severe weather warning remained in place for Taihape, and snow was falling on the Desert Road and would continue until early tomorrow morning, he said.
Mt Ruapehu had a nice dusting of snow, but a clear day down south meant little snowfall and cold temperatures.
Southland and southern Canterbury had experienced rain today, and isolated showers had been reported in Northland and north of the Harbour Bridge in Auckland.
Otherwise the central South and North Island have seen plenty of clear sky.
A chilly southwesterly wind continued to hit Banks Peninsula, Wairarapa and Wellington, Mr Law said.
"This won't change too much. It looks like it will stick with us over the next couple of days and bring chilly temperatures."
