Portland’s homeless shelters were filled to capacity Monday night as mounds of snow accumulated on streets and sidewalks and temperatures, combined with strong winds, produced what the National Weather Service described as “dangerously cold wind chills” – as low as minus 30 degrees – that were expected to last through early Tuesday.

On Monday night, the Oxford Street shelter, with a capacity of 154; and Preble Street’s makeshift shelter, which can accommodate 75; were both at capacity.

The city’s overflow shelter, at the General Assistance offices on Lancaster Street, can accommodate as many as 150 people, but officials said it was unlikely to fill up. People who seek shelter at Lancaster Street must sleep while sitting in chairs, because unlike other city shelters, it is not equipped with mats.

“The shelters will be crowded tonight. I’d be surprised if every square inch isn’t being used,” said Mark Swann, director of Preble Street, a resource center for the homeless.

Swann said Preble Street’s street outreach team and the city’s Homeless Outreach and Mobile Engagement – or HOME – team prowl city streets on most winter evenings looking for people who need shelter.

Rob Parritt, director of the Oxford Street Shelter, said the HOME team located three individuals who were intoxicated or going through drug withdrawal Monday. All three were transported to the Milestone Foundation – a shelter on India Street for people with addiction problems.

“January was a very difficult month for us. Part of it was a lack of resources and the other part was this miserable cold snap that we’ve been caught in,” Parritt said. “Everyone who had been camping out has come in.”

Parritt and a team of volunteers will fan out Wednesday night to conduct the city’s annual count of homeless people.

The U.S. Department of Housing and Urban Development conducts a “point-in-time” survey on one night in January every year during which volunteers count the number of homeless people living outside or in shelters in towns and cities across the country.

The annual count is required or the city faces the possible loss of $2.4 million in federal Housing and Urban Development funds used to support programs for the homeless.

Portland’s annual survey was supposed to have been conducted on Jan. 28, but Parritt got a waiver from HUD to postpone it for a week because of bad weather. Originally, the survey was scheduled for Wednesday evening, the day after a blizzard dumped two feet of snow on Portland.

“There was nowhere to park, the snowdrifts were huge and it just wasn’t safe to go out,” Parritt said.

Last year’s count on Jan. 29 tallied 497 homeless people in Portland, with all but 10 of them staying in shelters, according to the Maine State Housing Authority.

Statewide, 2,726 homeless people were counted during last January’s survey, compared with 3,016 individuals in January 2013. That was a larger year-to-year decrease than the 2 percent drop seen nationally.

But while the homeless population fell 10 percent nationally from 2010 to 2014, in Maine it grew by 14.6 percent in that same period.

On Wednesday night at 5:30, Parritt and a team of volunteers will gather at the Oxford Street shelter before heading out in vans and on foot to conduct the count, as well as to find homeless people who just need a place to stay for the night.

Parritt believes that getting the homeless into shelters isn’t a long-term answer to the problem.

“We don’t need more (shelter) beds. We need to develop more affordable housing,” he said.