For the past year, Rogelio Molina has lived at Reagan National Airport.

When he beds down at night on a heater between the security gates, he wears the same polo shirt he needs for his job as a cleaner at Washington Sports Club in Columbia Heights. He has a lock for his suitcase, wrapped with a cord around a pole. He has a friendly relationship with the garbage collectors.

Molina won’t be able to call the airport home for much longer. Starting Monday, Reagan National, which for years has been open 24 hours, is closing its doors from 11:30 p.m. to 4:30 a.m., shuttering a de facto shelter for dozens of homeless people that has grown under its roof.

Friday night into early Saturday morning, Arlington County staffers and advocates for the homeless circled the terminals, gently telling sleepers that in a few days they would have to move on. If the homeless stay in the airport Monday night, the officials explained, they could be arrested for trespassing.

“For years, National Airport has served as a sanctuary of sorts,” Arlington County Public Defender Matthew Foley said. “To their credit, for years, airport police have tolerated homeless folks as long as they haven’t presented a safety issue to others.”

But the numbers have been growing, according to airport police, and officials have decided that the sanctuary is a burden on the small overnight staff.

“The police have been indifferent, for the most part, until recently,” said a 63-year-old woman named Deborah, who said she had lived at the airport for a few months. Her sweater is stained and her fingernails are long; she says she “can’t be housed right now” because of fiberglass under her skin. For the past few days, she said, the police had been telling her that soon she will have to leave.

The decision was made several months ago and technically took effect at the end of September, said airport police spokesman Chris Paolino, so October was a month of transition. County ­mental-health professionals and volunteers already visit regularly to check in. Now they are there to warn people.

“Being open all night, or having a free flow of activity in and out of the airport does put our reduced staff under strain,” Paolino said. “We’re here to manage the airport, serve the traveling public.”

That public can still stay overnight. Police will ask those who linger whether they have tickets or a plane to meet, Paolino said.

On Friday night, early-morning fliers, airport staffers and the homeless snooze together in the airport’s older, smaller Terminal A. There is soft jazz playing instead of the main terminals’ CNN. A young woman says that she is not planning to stay long, that she just needs to find someone who will sell her a ticket in cash. To Maine, or Minneapolis. Two women in white ponchos say they are in a public space (they’re not) and have a right to be there (they don’t) and anyway, they’re really just waiting for a shuttle bus (unclear).

Those who said they made the airport home said they stayed there because they didn’t want to go to a shelter. Jerry Reddick, 64, said he used to stay at the District’s Community for Creative Non-Violence shelter at Second and D streets NW. Then a neighbor tried to set his bed on fire.

The floor of the airport, he said, “is not a bed, but at least it’s safe.” He had a big cup of coffee from 7-Eleven and a cardboard quart of soup from Giant resting at his feet. Like most part-time Reagan residents, by 11 p.m. he had his shoes off and a pair of headphones in.

Arlington officials said that a new shelter that just opened will be more hospitable, and they hoped those who make the airport their home would utilize county services there.

But it’s also already at capacity, although more temporary beds will open up now that hypothermia season has officially begun.

But it’s only open to Arlington residents. Officials said most of the airport sleepers are from outside the county. They can stay in the Arlington shelter for 96 hours before being directed or taken back to wherever they came from.

“I’m from anywhere you want me to be from,” says a woman named Dawn with a Batman backpack and a camouflage print jacket heading down the airport’s main hallway from the 24-hour Dunkin’ Donuts. “I just want a place to sleep.” She heard a couple of days ago that the airport was closing its doors during the midnight hours. She took some information from advocates, headed upstairs to greet a friend and bed down under the benches across from American Airlines.

Down in baggage claim at 1 a.m., delayed fliers wait for their suitcases while another homeless woman asks a county staffer for a hotel, and then to be left alone.

“You’re through playing games with my life,” she tells the staffer, straining to keep herself calm. “I want to shut Ronald Reagan Airport down on November 1.”

The staffer smiles and walks away. “Another one that’s going to be a problem,” said the county official, who asked that her name not be used. The staffers and volunteers plan to be back Monday, trying to convince people that it’s better to go to a shelter than to risk arrest.

“I know everything,” Molina, the cleaner, said to county staffers. But he said he doesn’t know where he’s going next. In January, he said he hopes to retire and return to the Philippines after 12 years and two bad marriages in America. He has been waiting for years for housing in Washington, he says. “How long will I wait?” he said. “I’ve already lost my hope.”