Trucks drive through a hoar frost beside Lake Benmore near Omarama in this file photo. Photo: Stephen Jaquiery
The NZ Transport Agency said the Lindis Pass highway between Tarras and Omarama and SH83 Otematata to Omarama had reopened.
"Extra care should be taken while driving in the region as winter driving conditions are present."
In Canterbury, SH8 Fairlie to Twizel and SH80 Lake Pukaki to Mount Cook have also reopened.
Elsewhere the Central Otago District Council said roads were mostly dry with patches of light fog and temperatures ranging from -3° to 2°C.
The Ranfurly area had light drizzle overnight which may cause slippery surfaces especially on bridges and shaded areas, the council said.
Crews were out gritting and would continue to monitor.
