Rachel Dyer, 42, was reported missing on December 21.
A police spokesperson said she may be in the Ashburton area.
"Police and Rachel's family have concerns for her welfare and would like to hear from anyone who can help."
- If you know anything, phone police on 105, quoting file number 201221/3738.
Meanwhile, Ngaire Ginders, 40, was last seen on December 29 in Christchurch and is described as 160cm tall with brown hair and fair skin.
A police spokesperson said they have concerns for her wellbeing.
- Anyone who may have seen Ginders should phone police on 105, quoting file number 210109/2083."
It comes after a public appeal for a missing teenager in Christchurch.
Brianna, 14, was last seen at her home on January 8 and is believed to be in the Christchurch area.
She went missing for two weeks earlier this month before being located safe and well. She has gone missing again.
- Anyone with information is asked to phone police on 105 and quote file number 201220/7305.