The Desert Road and the Rimutaka Hill Road are now open again.
Snow has been falling heavily on the Wairarapa side of the Rimutaka range.
NZTA Wellington operations manager Mark Owen earlier said State Highway Two was also threatened at Mt Bruce.
Extreme care is required on the Napier - Taupo Road because of the snow.
Drivers are advised not to stop on State Highway 46 from Rangipo - Otukou due to the possibility of flash flooding.
The Transport Agency says State Highway 87 from Outram to Middlemarch is closed and State Highway 94 to Milford Sound is closed.
Chains are essential on Porters Pass, State Highway 73.