It was a brief Big Chill.

After waking to winter’s first deep freeze Friday, when the mercury plunged below zero, Mainers can expect to see temperatures rise to the upper 20s by Saturday afternoon – albeit after receiving 4-6 inches of snow – and reach the 40s by Sunday.

Portland’s homeless shelter expected to be at capacity Friday for the second night in a row, said Rob Parritt, the shelter director.

He said 232 people checked in to the facility Thursday night, when the building at 203 Oxford St. quickly reached its capacity of 154. The overflow facility at the Preble Street Resource Center also was full, with 75 people.

“We had lots of folks coming in nice and early (Thursday),” Parritt said. “We were pretty full from 11:30 to 5 a.m.”

Staffers also patrolled Bayside every hour or two Thursday night to look for stragglers who were outdoors. Only one person refused to come into the shelter, Parritt said, and staff made sure that person was safe throughout the night and morning.

The day room the Oxford Street shelter usually opens at 2:30 p.m. was kept open all day.

“We want to help the crowding at Preble Street, but to also give people choices of where to hunker down,” he said.

Staffers at AAA Northern New England, which encompasses Maine, New Hampshire and Vermont, were fielding up to 280 calls every 30 minutes Friday morning, AAA spokesman Pat Moody said.

“It’s hoppin’, for sure,” he said. “The vast majority, 80 percent, are battery-related. Most of those are jump-starts, but we are doing a significant amount of battery replacements as well. Tires also are a problem in these temperatures.”

As New England Patriots fans should recall, air pressure decreases alongside temperature, meaning that a tire properly inflated on Thursday could become a problem in Friday’s cold.

Tires filled with air lose about 1 pound of pressure for every 10-degree decrease in temperature, Moody said. Nitrogen is an alternative that resists this effect, but is far more costly.

Moody expected the call center of about 50 would field between 4,000 and 6,000 calls Friday, up to triple the normal 1,800 to 2,000 they receive on a normal winter day.

Although it was the first serious freeze of the season, Friday’s low temperatures did not approach a record.

The low at the Portland International Jetport hovered around minus 2 degrees between 5-8 a.m., the National Weather Service said.

That was several degrees shy of the record for Dec. 16 set in 1951, when temperatures dipped to minus 9, said Andy Pohl, a meteorologist with the weather service in Gray.

Pohl said northwest winds blowing at 15-20 mph kept the apparent temperature even lower.

Portland Deputy Fire Chief Keith Gautreau said that on days of extreme cold, the biggest spike in calls can occur when temperatures eventually rise, and pipes that had frozen begin to thaw and burst.

Michelle Clements, a spokeswoman for the Portland Water District said a crew responded to a water main break in South Portland at 43 Pleasant St. Friday morning, but she did not know whether the rupture in the 6-inch pipe was weather-related.

Although Portland did not see any record-breaking cold, other places in Maine reached new lows. Records were set at airport weather observatories in Bar Harbor, Augusta, Auburn and Sanford, according to data from the National Weather Service and Weather Underground.

Atop Mount Washington, the site of some of the most extreme weather in the nation, winds were pushing 70 mph with gusts up to 95 mph, and with an air temperature of -26.

“It’s going to be quite the roller-coaster of weather coming up over the weekend,” said Margaret Curtis, a meteorologist with the National Weather Service in Gray, Maine.

Curtis said the bitter cold will ease overnight Friday into Saturday and snow will begin before daybreak around Portland.

The snow will continue most of the day, with about 4 to 6 inches falling in southern Maine, she said, and temperatures rising to the upper 20s by nightfall. The snow should end in the early afternoon, Curtis said, and temperatures will continue to rise overnight. Precipitation will return early Sunday, but may change from freezing rain to rain in Portland and along the southern coast of Maine, Curtis said, although it may stay frozen inland.

But by Sunday afternoon, skies will dry up, and the temperature will hit the mid-40s around Portland.

Next week looks dry, Curtis said, until the end of the week, and will be marked by seasonable temperatures, with highs in the 30s and lows in the 20s.

Staff Writer Edward D. Murphy contributed to this report.