Shirley Warrington, 85, was last seen on Main South Rd, Rolleston, at 7.30pm on Saturday.
Search and rescue teams were looking for Warrington yesterday afternoon.
A police spokesperson said they now believe she may be in the Ferrymead, Heathcote, or Horotane Valley Rd areas and are asking residents to check their properties including bushes, outbuildings and tree lines.
Temperatures reached -1.6deg C in Christchurch last night and -4.5 deg C on Sunday night.
There are concerns for her welfare as she has health issues.
Warrington may be disorientated and confused and is not dressed for the cold weather, the spokesperson said.
She is believed to be wearing the same black dress she is wearing in the picture.
If you have any information which could help locate Shirley, phone 111 and quote event number P047149632.
