A Washington region at wit’s end with winter dug out for the second time in 24 hours Friday, groaning under the weight of the area’s most significant snowfall in four years.

The region staggered into the day like a punch-drunk fighter, praying for this round of winter to end. Many people awakened to the scrape of snow shovels and listened for the deeper growl of snowplows. Owners of snowblowers felt that their investment had been vindicated.

The sun shone, but flurries and subfreezing temperatures were forecast for the weekend.

The morning commute got off to a slower start than usual, with slightly less traffic on the major roadways — in part because all public schools in the region were closed and the federal government opened two hours late.

Many local governments in the D.C. area said that most of their roads were plowed and treated by midday Friday and that crews were getting to side streets.

See how much snowfall has hit the region.

“We’re hoping we make really significant progress today,” said Joan Morris, a spokeswoman with the Virginia Department of Transportation. “It’s not curb-to-curb 100­­ percent perfect yet, but certainly people can get around the major roads.”

Maryland Highway Administration spokesman Dave Buck said the state’s numbered roads and interstates were plowed as of Friday night but that they were preparing to clear any additional accumulation that might fall Saturday morning.

“Yesterday we wanted to make it passable,” he said. “Today we went through and we’re currently pushing back on the shoulders, making sure the ramps are shoulder to shoulder.”

Montgomery County spokesman Patrick Lacefield said warmer temperatures were softening the snow and making it “a pretty good day for plowing.” County crews were scheduled to go into central business districts in Bethesda, Silver Spring and Wheaton with trucks Friday night to load snow and haul it away.

In the District, Department of Public Works spokeswoman Linda Grant said plowing operations were largely over.

“Whether plowing or salting, we’ve been over virtually every street,” Grant said, “but we always know there is going to be some street . . . that is missed, so we ask residents to call 311 to report that you need attention to your street.”

Although there was general agreement from almost everyone — except schoolchildren — that the region’s cold, harsh winter had lingered too long, the findings of one researcher suggested they should buck up.

You step in a slush puddle that turns out to be shin-deep and now your feet are icy-wet — in that way, winter can be annoying. But the notion that cold and a gray sky are depressing, that bleak weather puts the populace in a communal funk — the so-called winter blues — appears to be a myth, said David Kerr, a clinical psychologist who has studied the effect of climate on mood.

“People have long assumed that most of us get depressed by winter automatically,” said Kerr, who teaches at Oregon State University. “That’s what I wanted to test: Do most people show this trend? Does winter mean that most people are more sad, they have trouble sleeping, trouble with appetite?

“And the answer, I believe, is no.”

Here’s why he thinks that:

At the behest of researchers, 760 people in Iowa and Oregon have been recording their moods during various seasons, some for as long as 17 years. The information has been used in studies of how conditions affect dispositions. Kerr and Jeff Shaman, a Columbia University researcher, wanted to know how the weather made people feel.

So they compiled highly detailed weather data — specific to time and place — for each person’s notes about moods.

“We found a modest association between time of year and depressive symptoms, so that, yes, some people were slightly more depressed in winter,” said Kerr, whose study was published last year. “But it was so modest that it did not seem to us to be something that the average person would even notice.”

Because the idea of the winter blues is so popular — reinforced by winter advertisements for getaway warm-weather vacations — most people assume that other people must be feeling blah in February, that bad moods are commonplace this time of year.

“But we were surprised to find that that just isn’t the case,” Kerr said.

On the other hand, not everyone was filled with an honest desire to help a fellow citizen cope with the trials of winter.

On Thursday night, a motorist said he was stuck in snow on Marcy Avenue in the Oxon Hill area of Prince George’s County. A man came up and asked if the driver needed help. Rather than help, he jumped into the car and demanded the driver’s property, police said.

They said the robber fled when police arrived, but police took a man into custody and recovered the driver’s wallet and cellphone.

Snowfall varied around the D.C. region, from nearly 18 inches in Gaithersburg to eight in Alexandria.

It was the heaviest snowfall in the area since the “Snowmageddon” storm of 2010.

Nearly 1,500 flights across the country were canceled.

At Reagan National Airport, 74 flights were canceled Friday morning, and 39 were canceled at Washington Dulles International Airport, according to FlightAware, a Houston-based flight-tracking firm. At Baltimore-Washington International Marshall Airport, about 30 flights were canceled. Dulles had three runways open Friday, and Reagan had its main runway open. None of the runways were closed Thursday at BWI.

The storm was linked to at least four deaths in the Washington region. A Virginia Department of Transportation contract truck driver helping clear roads died Thursday after he was struck by another VDOT truck in Ashburn. Virginia State Police said Lovo Guevara Geovany Arnoldo, 32, of Vienna pulled off the road and was standing behind his truck when he was hit.

In Howard County, two men in their 50s collapsed and died after shoveling snow, one in Woodstock and the other in Columbia, the fire and rescue department said. A third man was found dead outside, but officials did not know the cause.

A Fairfax County man died Thursday after helping a neighbor clear a snow-covered driveway, his family said.

Peter C. Williams, 67, was using a snowblower on a hilly driveway in the 1800 block of Collingwood Road in the Alexandria section of the county when he collapsed, and later died, his former brother-in-law John Hooff said.

Williams, an attorney, was active in the Rotary Club of Alexandria. “He was a friend to everyone,” Hoof said “It’s just really sad. He died trying to help.”

At least 21 people died along the East Coast, including a pregnant woman who was struck by a snowplow in New York City and whose baby was then born by Cesarean section, the Associated Press reported. The newborn was reportedly in critical condition.

Dana Hedgpeth, Bill Turque, Aaron Davis, Matt Zapotosky, Julie Zauzmer, Caitlin Gibson, Patricia Sullivan, Antonio Olivo, Luz Lazo, Justin Jouvenal and Martin Weil contributed to this report.