The facilities are Waikari, Darfield, Oxford and Ellesmere hospitals.
A spokesperson for the Canterbury District Health Board said planning is under way to move 23 residents to alternative private facilities.
Incident controller for the Canterbury Health System's Omicron response, Tracey Maisey, said the health board is having to make this decision now due to its ability to staff these facilities through the peak of the Omicron outbreak as staffing resources become strained.
"One of our main concerns was that during the outbreak we will not be able to sustain safe staffing levels with appropriately trained staff in these facilities, and this was a major risk that could have had a serious adverse impact on our residents.
"We are therefore moving with urgency to assess each patient and connect with residents' families or next of kin to decide on a suitable alternative facility for each resident. We take our responsibility for their care very seriously and will do everything we can to ensure their safety and wellbeing," she said.
Maisey said finding suitably qualified local staff in rural areas can be very challenging, "which is why we need to look after and make the best use of our people".
"As part of our whole-of-system response plan, we will be working with the staff from the facilities we have closed temporarily to identify areas they can be redeployed to."
Maisey said this relocation of residents is not ideal and will have its challenges, but the support and assistance of family members is being welcomed and appreciated.
"We will take care and be sensitive to the needs and concerns of patients and family to ensure a smooth transition.
"We will be looking to relocate them as soon as a new home for each resident is agreed. The move to their new home will be temporary.
"Residents should be back in these hospital facilities within six weeks of the Omicron outbreak's peak."