Photo provided by National Weather Service

Chris Miller sat on a duffel bag on a Camp Street sidewalk Monday afternoon, wishing he were back in California.

He wore a thick jacket over a hoodie over two shirts over a torso that shivered in a bitter cold that New Orleans hasn't felt in quite a while.

It was a tick or two above freezing at mid-afternoon and getting colder fast as the sky darkened and an icy chill squatted over the city, with plans to stick around for the week.

Miller, 41, said he arrived in the city a month ago and found work but soon got jumped by three men in the French Quarter, cracking his femur. The incident and a strung-out roommate conspired to leave him jobless, homeless and waiting Monday for the Ozanam Inn shelter to open its doors for the night, he said.

"That's the only thing I can do right now," he said. A walker stood within reach as Miller described a radiating pain in his right leg.

"It's a metal plate. It's cold. Like a numbness, but sometimes it's a shooting pain," he said. "It's freezing out here."

The arctic blast that has swept across the eastern United States from north to Deep South is expect to remain in the New Orleans region for a few more days. A National Weather Service forecaster here said lows could dip into historic territory.

Low temperatures from 20 to 28 degrees were expected Monday and Tuesday nights over most of the area, with temperatures dipping into the upper teens some places north of Lake Pontchartrain, according to a National Weather Service advisory at 4 p.m. Monday.

Wind chills of 5 to 15 degrees were forecast across much of southeastern Louisiana and southern Mississippi.

Lows in the low to mid-20s were expected to continue through Thursday night, with sub-freezing temperatures possible into the weekend.

In St. Tammany Parish, officials announced that the parish warming shelter, at the Giving Hope Retreat Center of the New Orleans Mission in Lacombe, would remain open through Saturday.

A "nor'easter-type system" off the eastern seaboard is helping to slow a warming trend, keeping a mass of cold air over a wide swath of the eastern U.S., said Gavin Phillips, a forecaster with the National Weather System.

The weather service said Monday night's low could make it the coldest New Orleans night since 2014.

Historic records in the low-20s, recorded in 1983 and 1984, could well fall, Phillips added. The fact that a bitter chill will remain in place over a prolonged period improves the odds.

"Tonight's not our only shot. We've got four or five cool nights coming up. It's like throwing darts. We might break it one night," he said. "But it's not like we're going to see it destroying a record (by several degrees) or anything."

Hard-freeze warnings mean sub-freezing temperatures are "imminent or highly likely," threatening crops and other vegetation.

Phillips noted that the cold front is sweeping east of the Rockies, with no effect, for instance on Los Angeles, which Miller said he left after a spat with his girlfriend.

In L.A. on Monday, it was sunny with a high of 71.

"This is the first time I've ever had to deal with this," Miller said.

Follow John Simerman on Twitter, @johnsimerman.