After enjoying a white Christmas, Mainers got out the long johns and stoked the fire Sunday in preparation for the season’s coldest weather so far.

The National Weather Service posted a wind-chill advisory for the entire state. Overnight low temperatures were expected to range from around zero along the coast to 20 below in northern sections.

Wind-chill readings were set to plummet to 30 below and even lower, according to forecasters.

Meteorologist Eric Schwibs said the outlook was for at least several days of cold weather but no record lows.

“We’re going to stay cold right through the middle part of the week,” he said. “Basically, once the cold air gets in here, it’s going to stay around for a few days.”

Light snowfall Saturday brought Mainers a white Christmas without the traffic problems that accompany a major storm. The situation changed on Sunday, however, when snow squalls Sunday reduced visibility for motorists in various sections of the state.

State police in the Bangor area and the Penobscot County Sheriff’s Department were busy responding to accidents caused by the wind and snow.

Penobscot County Sgt. Ron Green said his department responded to seven accidents spread all over the county by late Sunday afternoon, “mostly fender-benders” with no serious personal injuries. Three of them were in the Hudson area, said Green.

Trooper Dennis McLlellan said he responded to 12 accidents during the day. Two people received minor injuries Sunday morning on Route 1A in Holden when they were forced to swerve out of the way of a vehicle that failed to stop for a stop sign at the Bagaduce Road, said the trooper.

Alphonse Haskell, 57, of East Corinth was driving his mother, Doris Conary, 83, of Stonington, back to her home when the accident took place. A car identified only as a white Mercury Cougar failed to stop at the stop sign, and Haskell swerved his 1988 Chevrolet pickup truck to avoid a collision.

The truck ended up in a ditch, while the other vehicle didn’t stop. Neither Haskell nor his mother was wearing a seat belt, said McLlellan.

Michael Dow, 34, of Orono was injured Sunday afternoon while traveling on Interstate 95, according to the trooper. The accident occurred at the Odlin Road overpass. The state police were notified at 2:31 p.m.

Dow was heading north in the passing lane and returned to the travel lane when he lost control of his vehicle, a 1991 Dodge sedan. The car hit the guardrail, spun around, went over an embankment, and came to rest in a gully, said McLlellan. About 50 to 60 feet of the guardrail was totaled, said the trooper.

The driver wasn’t wearing his seat belt at the time of the accident. No other vehicles were involved, said McLlellan. Dow was taken by Capital Ambulance to Eastern Maine Medical Center, where he was treated and released.

McLlellan blamed the accident on inappropriate speed for the weather conditions.

In Trenton, a 31-year-old woman lost control of her 1993 Aerostar van on the Bayside Road and skidded into a tree. Renee Townsend, 31, of Trenton was taken to Maine Coast Memorial Hospital with complaints of injuries to her legs and chest. Her 2 1/2-month-old baby was strapped in a car seat and was unhurt.

This was the only serious accident among numerous slip and slide incidents that occurred on roads in Hancock County.

On a happier note, the day after Christmas marked the start of one of the busiest weeks of the season for Maine’s ski areas. Sunday River saw the first regular run of its ski train between Portland and Bethel.

“Everything went just like clockwork,” said Skip King. The Sunday River spokesman said 250 people rode the train, which pulled into Bethel at 9:01 a.m., one minute behind schedule.

Riders ranged from entire families to groups of high school students, some of whom boarded the Silver Bullet Express at Auburn.

The train is scheduled to offer daily round-trip service this week before reverting to its regular Thursday-to-Monday schedule.

Some of the Mainers who weren’t on the ski slopes headed to stores and shopping malls to return unwanted presents or take advantage of post-Christmas sales.

The Bangor Mall was busy throughout the day despite miserable weather during the afternoon.

“It’s snowing, it’s icy, it’s just awful out there,” said Tammy Jones. She said the weather didn’t deter shoppers on what is traditionally one of the busier days of the season.