Search teams will spend a cold night in bush after failing to find an overdue tramper missing in the Hunua Ranges, south of Auckland.

Searchers spent Sunday scouring the bush for the 36-year-old man, who was last in contact with friends about 3.30pm on Saturday, when he sent a text message saying he was delayed.

He was poorly prepared for a cold night outdoors, wearing a light-weight jacket and three-quarter-length shorts and carrying a day pack, police say.

Temperatures on Saturday night dropped to about minus 3C, and a similar temperature was expected on Sunday night, when two search teams will stay in the ranges overnight to resume searching on Monday morning.

Air force Iroquois helicopters will use night-vision equipment to continue looking for the man on Sunday night, and assist with the search again on Monday.

Police are appealing for anyone who was in the Mangatawhiri or Waharau areas of the Hunua ranges on Saturday to come forward, regardless of whether they saw the missing tramper.