The Desert Road stretch of State Highway 1 is closed this morning due to snow and ice.
The New Zealand Transport Agency said detours were in place via State Highways 46, 47, 4 and 49.
Southbound motorists should use SH46 and SH47 to National Park, turn left on to SH4 then left on to SH49 to Waiouru, the NZTA said.
The reverse route was advised for northbound motorists.
