Has the threshold for snow days fallen?

Statistics proving the snow-day standard is softer than it once was are hard to come by. The state doesn’t collect them. The Boston public schools have compiled snow-day numbers going back only 20 years, and they don’t include information about storm size. Even so, simply comparing snowfall totals over time could be inconclusive, because a variety of factors — like timing — contribute to a storm’s wallop, or lack of one.

Without numbers, why is there this widespread belief that we’ve turned weak?

Paul Dakin, superintendent of the Revere public schools, blames the recent trend of canceling school the day before, as opposed to the morning of, a snowstorm. The increased sophistication of weather forecasting models makes the early calls possible, and they help parents plan for child care, or at least give them more time to stress. But the one-two punch of correct calls made way, way before the snow begins and incorrect calls on storms that fizzle arm those cranky folks who say we were hardier souls “back in the day.’’

“I honestly don’t think we’re calling more days,” said Dakin, who’s been calling snow days for 20 years. “But people are calling us wimps.”

As snow-day fatigue grows — the Boston public schools have called three so far this year, plus an extra vacation day, but had class Thursday — many seasoned educators, while not conceding they are quicker to call off school, supply explanations for erring on the side of caution.

After all, as the decades have passed, American society has become increasingly safety-obsessed, weather-crazed, social media-driven, traffic-jam phobic, risk averse, and litigious.

In 2014, it takes a brave superintendent to send out school buses when meteorologists gleefully warn of “snowmageddon” and “snowpocalypse.” Especially when news of bungled snow calls happening thousands of miles away — most recently in Atlanta — are headline news here.

Matthew Malone, the state’s secretary of education, says calling a snow day can be a “lose-lose proposition.”

“The fear is of getting beat up by the media and by the parents,” he said. “One thing you can lose your job over is not whether you didn’t raise student achievement, but making a bad snow call.”

Increased, if unspoken, pressure to call snow days may have led, at least in part, to a trend toward starting the entire school year earlier, a strategy intended to allow districts to fit in the state-mandated 180 days by June 30 without having to eat into vacation weeks. For flexibility, schools build an additional five or more days into the schedule.

“If you look around the state, a lot of schools now start before Labor Day,” said Thomas Scott, executive director of the Massachusetts Association of School Superintendents. “Fifteen years ago that wasn’t the case.”

The alleged lower standard for snow days comes as the amount of snow is actually decreasing. The average New England winter sees approximately two fewer weeks with snow on the ground than in the 1960s, said Pamela Templer, an associate professor of biology at Boston University who has conducted snow-related research.

“Clearly this winter is an outlier, but the general trend has been for our region to receive less snow,’’ she said, “and this trend is expected to continue.”

But even as average snow totals drop, the number of cars on roads grows and that can increase a storm’s impact. In 1977, for example, the average weekday traffic count on the Mass. Pike between the Newton Corner and Allston/Brighton exits was 77,000 cars, according to the Boston Region Metropolitan Planning Organization. In 2010, 141,000 vehicles were on that stretch. On Interstate 93 in Medford, the traffic count jumped from 123,000 per day in 1977 to 182,000 in 2010.

With the gridlock of December 2007 fresh in the Commonwealth’s collective memory — schools and businesses sent people home early because of a storm and an epic traffic jam ensued — officials are more wary of sending kids out on the roads. Consider Governor Deval Patrick’s move to ban nearly all traffic from Massachusetts roads as a giant nor’easter swept through the region last February.

That storm was a monster. The tension for superintendents comes when a storm forecast is less clear-cut.

“Anytime you go against the grain, you have people saying, ‘What kind of stupid idiot are you?’” said Scott.

While no one can recall a superintendent actually losing a job over a storm, Newton Superintendent David Fleishman says he’s been “beaten up” over snow-day calls. He recalled an instance in the district he previously ran in New York, when a parent was angry because Fleishman didn’t call a snow day.

“He’d gotten into a fender bender taking his kid to school during a surprise morning storm,” Fleishman said, “and he said he wanted to send me the bill.”

Some educators say the real villain is not the snow or even the traffic, but the media — TV meteorologists in particular.

“The weather people start licking their chops when they see a storm coming,” said Matthew King, a veteran superintendent, currently heading the Rashi School in Dedham.

“They get all hyped up about it, and that gets people anxious,” he said. “The number of parents who call to ask if there’s going to be a snow day is way, way increased from what it used to be. They whip people up a week in advance.”

But who’s to blame for TV-generated storm frenzy? Viewers are, it seems. In surveys, they repeatedly say they watch local news largely for the weather, said Nick Lawler, vice president of the consulting firm Frank N. Magid Associates. “The seven-day forecast is extremely important to viewers.”

A recent study by an assistant professor at Harvard’s Kennedy School shows that snow days don’t have a negative impact on learning. Yet, with such days often now called the night before, students often miss out on one joy from yore.

“I remember being a kid and the greatest thing was turning on the TV in the morning and looking to see if there was a snow day,” said Eric Fisher, WBZ-TV News’ chief meteorologist. “That’s been taken away a little.”

Schools may even be depriving our kids of future bragging rights to a good old-fashioned Yankee childhood, in which kids walked to school in blinding snowstorms. When graduating seniors at Newton South High School shook the superintendent’s hand after getting their diplomas last June, a number of students made sure to thank him.

“But not for a great education,” Fleishman recalled. “For all the snow days. I called six last year — a career high.”

Beth Teitell can be reached at bteitell@globe.com. Follow her on Twitter @bethteitell.