In Scituate, the high-water mark carved into snow and ice after Thursday’s flooding took government scientists by surprise.
Off parts of Cape Cod, freezing temperatures transformed ocean waters into ice, a meteorologist said.
In some spots, it was too cold Saturday to have fun. Ski destination Killington Resort in Killington, Vt., closed due to the cold, and the Boston Winter festivities on City Hall Plaza were shuttered for the second day in a row.
The arctic freeze gripping Boston is expected to culminate Sunday, when temperatures will plummet to minus 3 degrees in the early morning and the windchill to minus 21, according to the National Weather Service.
In Boston, the record low for Jan. 7 is minus 2, set in 1896, meteorologist Bill Simpson said.
And Worcester will be even colder.
The temperature is expected to hit minus 7 degrees early Sunday morning in Worcester, where the current record low for Jan. 7 was set in 1942, when the thermometer plunged to minus 5 degrees, Simpson said.
An advisory for Eastern Massachusetts warning of windchills dropping as low as minus 25 degrees is in effect through 10 a.m. Sunday, the weather service said. Sunday’s high temperature in Boston is predicted to be 16 degrees.
Gardner Bent and Gordon McQuaid, who work for the US Geological Survey, spent part of Saturday measuring the effects of the recent stretch of brutal weather in Scituate by documenting high-water marks from flooding during Thursday’s nor’easter.
In one spot on Scituate Avenue, a high-water mark came in over Bent’s head.
“I was pretty surprised it got that high in here,“ he said. “We knew that . . . the ocean water level was going to be up, but I didn’t expect that.’’
The height of the floodwaters was cut into ice and snow on fences, utility poles, and other structures.
Bent and McQuaid examined a wooden fence that was topped with a thick facing of snow, but bare on the bottom, which had been submerged in the flooding.
“The cold right now kind of solidifies it and keeps it there,“ McQuaid said of the snow line on the fence. “If it was really warm, it would kind of melt away, and we wouldn’t really be able to see what happened. So this cold kind of helps us out.“
Polar landscapes were visible in parts of Buzzards Bay and Nantucket Sound as ice formations took shape, said Ron Horwood, a meteorologist with the Northeast River Forecast Center.
“It’s an interesting phenomenon that we can get in New England during these colder winters,’’ he said. “Normally, we won’t see this type of ice formation in an average winter.’’
But relief is on the horizon.
On Monday, the temperature is expected to rise above freezing, Simpson said, and temperatures in the mid- to upper 40s are forecast for the end of the week.
Rain is possible Thursday night and Friday, and next Saturday could bring rain and snow, the weather service said.
In the meantime, Revere resident Joe LaVigueur, 69, said he is relying on electric space heaters to get him through the end of the deep freeze.
Water from Belle Isle Marsh flooded his home during Thursday’s storm, breaking his heating equipment and hot water heater.
“I’m keeping a couple of rooms upstairs above 50 degrees. It’s like a heat wave compared to this,’’ he said.
Mount Washington Observatory in New Hampshire boasted a temperature of minus 17 degrees and a windchill of 62 degrees below zero Saturday afternoon, making it one of the coldest places on earth behind several spots in northern Canada and Russia. By 9:30 p.m., the temperature had fallen to 22 degrees below zero with a windchill of minus 69.
As of Saturday night, wind was gusting to 81 miles per hour at the summit, 6,288 feet above sea level.
Delays on some subway and commuter rail lines meant frigid waits for trains.
The MBTA said there were periodic delays throughout the day, according to Twitter posts.
Keolis Commuter Services, which runs the commuter rail system, reported delays for some trains on several lines. The delays were announced on Twitter and attributed to mechanical, switch, and signal problems.
The Massachusetts Department of Transportation on Saturday advised the traveling public to be aware of heavy winds blowing snow from drifts into the roadways, as well as frigid temperatures that might cause road surfaces to freeze.
A Massport spokeswoman said Logan Airport had not been significantly affected by the cold.
Massachusetts General Hospital had seen six patients in 24 hours for cold-related injuries by early Saturday afternoon, said Dr. Brian Yun, an emergency physician at the hospital. Four were mild, and the patients were not admitted; two had more serious conditions, Yun said. One person had such severe frostbite that doctors had worried the person could be at risk for losing digits, Yun said.
This winter, he said, the hospital has had more cases of cold-related injuries than in past seasons.
A spokeswoman from Boston Medical Center said that hospital had also seen “numerous cases of frostbite, some bad cases of hypothermia, and a number of slip and falls.’’
The sustained low temperatures have stretched city resources for vulnerable homeless people.
“We are still hanging in there, but I will tell you it has been exhausting,’’ said Barbara Trevisan, communications director at the Pine Street Inn. “Everyone has stayed alive — we consider that a victory.’’
On Thursday during the storm, she said, Pine Street Inn outreach workers had to dig a homeless person out of a snowbank.
On Friday night, she said, the shelter’s outreach van came across a man who had hypothermia and frostbite, and summoned an emergency medical crew to take him to a hospital.
Pine Street Inn shelters are serving extra meals and sleeping extra guests, she said, and providers across the city are doing the same. South Station, which has opened its doors to homeless people to stay overnight, will remain open for “shelter in place’’ through the weekend, Transit Police Superintendent Richard Sullivan said.
The Cambridge-based Islamic Society of Boston opened its mosque to people seeking refuge from the cold and served soup and hot cocoa, said Amr El-Fass, the organization’s executive director.
More than 1,700 homeless people have been sleeping in shelters in Boston, said Jim Greene, assistant director for Street Homeless Initiatives at the city’s Department of Neighborhood Development. And Friday night saw the lowest number yet of homeless people who refused to come inside, he said: About 10 spent the night outdoors, compared with about 40 last week.
He urged the public to look for homeless people in distress, especially around homeless shelters and hospitals. If someone looks like they are in trouble, call 911, Greene said.
Correspondent Jacob Carozza contributed. Evan Allen can be reached at evan.allen@globe.com. Follow her on Twitter @evanmallen. Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her on Twitter @lauracrimaldi. Jeremy C. Fox can be reached at jeremy.fox@globe.com. Follow him on Twitter @jeremycfox.
