Police say the search for a tramper missing in the Hunua Ranges, south of Auckland, has so far failed to find any trace of him.
Ronnie Fong, 36, hasn't been heard from since he went for a walk on Saturday.
Weather in the area on Monday was poor but about 70 people, including police and Air Force personnel, search and rescue specialists and volunteers, have been looking for Mr Fong, using quad bikes, motorcycles and helicopters. The search was to continue into the night.
The missing man is not equipped for the cold weather, and isn't an experienced tramper.
Police say he was wearing a light-weight jacket and three-quarter length pants and was carrying a day pack.
The sergeant leading the search, Dene Duthie, says Mr Fong's jacket is not waterproof and he has some supplies including energy bars, energy drink, and water.
Sergeant Duthie says the terrain is rugged and can be difficult to navigate.