Police are warning drivers in the western Bay of Plenty that there is black ice on the roads.
Sergeant Mark Holmes said State Highway 29 over the Kaimai Ranges and State Highway 36 between Rotorua and Tauranga are particularly bad.
He said the roads were open but drivers should take “extreme caution”.
“Black ice has once again formed on sections of State Highway 29 between Ngamuwahine Road and the Kaimai Summit.
“Police highway patrols are monitoring the road conditions and roading contractors are spreading grit but extreme caution is required,” Mr Holmes said.