Christchurch City Mission staff are “genuinely worried” they will soon find a dead rough sleeper as the cold snap continues and they see more elderly people living on the streets.

In a Facebook post on Tuesday, the social service agency said the past week has been tough for people without a safe, warm home.

The temperatures in Christchurch fell to -4.5C on Monday. While the low on Thursday is expected to be 7C, it is forecast to again drop to below 2C this Saturday.

The city mission's outreach team has been checking the streets to ensure members of the homeless community - including people sleeping in cars - are okay.

“This has been a brutal week for rough sleepers in Christchurch, and our Outreach staff have been busy checking on everyone including those who are trying to get through the night in a car,” a city mission spokesperson said.

“Our guys are genuinely worried they are going to find someone who has not made it through the night.

"And that is especially so because we are seeing more elderly people now out on the streets.

"They came across an 82-year-old last week who, for his own reasons, chose to stay out.

“For those clients who we can’t help in our emergency shelter, the guys offer dry warm clothing and sleeping gear, and compassion.

“As one of our guys said: ‘When it’s that cold how can you make decisions? How can you think straight? Winter is tough but we are out there too, helping as much as we can’.”

-Allied Media