Mainers are bracing for frigid temperatures that will grip the state for days, posing a threat to water pipes, car batteries and the safety of people forced to be outside.

Temperatures Tuesday night and Wednesday morning are expected to drop into the single digits. By Thursday night, temps likely will be 5 to 10 below zero along the coast and 15 to 20 below in the mountains.

And daytime temperatures won’t be much warmer. High temperatures at this time of the year typically approach 30 degrees, but Thursday’s daytime high is expected to be in the single digits, which would set a record for that date.

“It will continue to get colder and colder each day through Thursday,” said Andy Pohl, a meteorologist with the National Weather Service in Gray. “With those types of temperatures, if we have any wind at all, we’ll have dangerous wind chill as well. That could bring wind chill values to minus-10 to minus-20. That’s no fun.”

Long-term forecasts indicate the frigid air is likely to stay well into next week.

Forecast from National Weather Service in Gray

In Portland, officials at the Oxford Street Shelter are stepping up community outreach to get as many homeless people out of the elements and into the shelter as possible as the mercury plunges to single digits. The shelter now stays open 24 hours, which allows many people to stay inside during the days instead of heading out onto the streets after breakfast, said Meaghan Void, assistant director of the shelter.

“The risk of exposure and the potential for negative outcomes greatly increases when the weather gets as cold as it does in Portland,” Void said. “Our goal at the Oxford Street Shelter is to keep people in, not put people out.”

Shelter officials also are reviewing cases in which past residents at the shelter have been ordered to stay away because of conflicts or misconduct, possibly lifting those restrictions to allow some people back into the shelter if it is safe for other guests and staff, said David MacLean, director of social services for Portland. If a person cannot safely be allowed to return to Oxford Street, staff tries to connect them with partner agencies and other resources to find shelter.

The cold temperatures come on the heels of the biggest Christmas snowstorm in 15 years, an intense but short storm that prompted the National Weather Service to issue a blizzard warning for the entire state and that dropped more than a foot of snow in some areas. There were widespread reports of snow falling at a rate of 2 to 4 inches an hour Monday morning, with one report of snow falling at 5 inches an hour, according to a weather service meteorologist.

“It was fast moving, but the intensity was pretty significant,” Pohl said. “You don’t see those snowfall rates that often.”

The current cold spell could rival some of the longest, most intense on record in Portland. The current 7-day forecast does not have Portland rising above 20 degrees, with most nights below zero. Graphic by the National Weather Service in Gray

New Gloucester hit the snow jackpot on Christmas, recording 13.1 inches of snow, the weather service said. Other Cumberland County totals include 12.1 inches in Windham, 11.5 inches in Standish, 8 inches in South Portland and 4.5 inches in Falmouth. York County snow totals ranged from 11.1 inches in Hollis to 3 inches in Ogunquit.

Multiple communities in Androscoggin County, including Leeds and Winthrop, reported just over 12 inches of snow.

Sugarloaf in Carrabassett Valley received 10 inches of fresh snow Monday on top of the nearly 2 feet of snow that fell there in the past two weeks. The snow fell at the start of the busiest week of the season for the ski resort, although the cold will make it more important for skiers to cover exposed skin and take frequent breaks to warm up.

“(The forecast) is not ideal like we’d like to see, but the fortunate thing is the snow is incredible,” said Ethan Austin, the resort’s director of marketing. “The skiing is really good and as long as people bundle up they’ll have a great time.”

The cold snap already has led to an unusually high number of calls for service from AAA, spokesman Patrick Moody said. By Tuesday afternoon, the company had received 3,330 service calls in Maine, New Hampshire and Vermont, considerably higher than an average winter day of 1,500 to 2,000 calls.

“We’re anticipating the rest of the week with temperatures dropping to negative digits it will be extremely busy as well,” Moody said.

Most of the calls were for people who needed help getting out of snowy driveways, had dead car batteries or had locked their keys in the car while warming it up, he said. He suggested people check car batteries that are more than a couple years old to make sure they are properly charged.

At Pine State Services, a Westbrook plumbing and heating contractor, employees are gearing up for a weekend of emergency calls.

Jim Marcisso, a partner at the business, said he is already starting to get calls from people concerned that their heating systems aren’t working properly. But he said the real surge won’t start until about 24 hours after the cold sets in.

“The first wave of subzero temperatures is really what does it,” Marcisso said. “We can get 50 to 60 calls a day through those times.”

To avoid frozen pipes and emergency calls, Marcisso said homeowners should check on their heating systems sooner rather than later.

He advised people to make sure their windows are all closed, their fuel levels are safe and drafty areas are insulated as well as possible from the cold. To avoid frozen pipes, he suggested keeping the house warmer than usual and routinely turning on underutilized faucets to get the water moving.

“Just be safe,” Marcisso said. “Living in Maine this time of year, we’ve got to look out for each other.”

The National Weather Services says people should prepare for the cold temperatures by knowing the signs of frostbite – numbness and skin that is red, white, bluish-white or grayish-yellow in color – and hypothermia – confusion, lethargy and slurred speech. Frostbite can happen in minutes when skin is exposed to extreme cold, while hypothermia sets in when the core body temperature drops below 95 degrees. The weather services advises people to keep skin covered, stay inside when possible and drink fluids because hydration increases the blood’s volume.

Pohl also suggested people consider putting a winter safety kit in their car that includes extra gloves and hats, blanket, a flashlight with battery, snacks, socks and a cellphone charger.

Staff Writer Megan Doyle contributed to this report.