Headteachers are angry at being told they should not have shut schools earlier this week during the worst snowfalls in 18 years.
Parents' groups gained huge publicity by claiming the closures set a bad example to pupils, while business leaders criticised the disruption to working life.
Estimates of the number of schools that closed varied, but around 8,000 were shut on Tuesday.
Mick Brookes, general secretary of the National Association of Head Teachers, reacted angrily to the criticism.
"The attacks on schools are absolutely outrageous," he said.
"The first responsibility of heads is the safety of children. The weather forecast said, `Don't make journeys unless absolutely necessary.' It did not then go on to say, `Unless you are a child, parent or work in a school.'"
Heavy snow fell across most of the country on Monday, bringing London and the South East to a virtual standstill. The forecast was for more snow on Monday night, prompting many schools to give parents early warning of closures.
Bradford and Birmingham decided all schools would shut. But when the severe weather failed to show, schools came in for criticism.
John Dunford, general secretary of the Association of School and College Leaders, said: "These criticisms are quite unwarranted. Heads try to keep schools open if they can, but it is a very difficult decision.
"It seems headteachers always get the blame for the ills of society. I don't think they should get the blame for the weather."
Margaret Morrisey, of the Parents Outloud campaign group, led the criticism of schools.
"We are giving children the message that when things get difficult you should just stay at home and have fun," she said.
"In my day, all the children sat in the hall and you had the headteacher and one or two others reading to the children, doing quizzes - all those kinds of things.
"It was great fun. You were at school, you did get to go in the playground, you did get to play in the snow. We were taught things like not to make snowballs out of ice - all the things you have to learn as you grow up."
Chris Pearson, head of Goldstone Primary in Hove, opened on Tuesday after being closed on Monday.
He said: "On Monday, I walked the four miles to school. It was way too dangerous to drive. I made the decision to close at 7.45am. My biggest concern was children's safety. Getting in was an arduous and quite dangerous journey.
"There were other considerations. Our cook lives on top of a hill - she couldn't get the car out. There were no buses, and a taxi got stuck in the snow trying to get to her.
"On Tuesday, every teacher could get in. I rang parents to say we were open and every parent, apart from one, said `brilliant'. A couple of schools nearby closed, and I would have closed them too because they are at the top of a very steep hill."
Avtar Mangat, head of Wilkes Green Junior in Birmingham, opened on Monday and closed on Tuesday. He said: "On Monday, there was a power failure from 1pm to 3pm. The forecast was that the weather would get worse and parents started ringing, asking to pick their children up early.
"We contacted the local authority and took into account responses from parents and colleagues. There were treacherous conditions coming from home to school. People have to walk along side streets and they are not gritted.
"It's not that there was a bit of snow and the school closed - this was an informed decision."