By Angela Harrison
Education reporter, BBC News
Icy conditions around a school can cause a school to close
Schools should open where "reasonably practicable" in the severe weather, England's education department says.
With about 8,500 UK schools shut, the government is reminding schools that "every lesson counts".
Just under half of England's schools were closed on Wednesday and today the number was about 7,400.
In Scotland and Wales more schools opened. Scotland had 13% of schools shut and Wales about one third. In Northern Ireland, just 24 were closed.
There have been claims that some schools have closed because they are worried their absence figures might damage their Ofsted reports.
Schools inspectors consider absence figures as part of their inspections. If a school is closed, there are no absences.
Every lesson counts
On Wednesday, more than 9,000 of England's 21,000 schools were closed and the indications are that the picture is similar today.
, 64% of schools were closed on Wednesday - but now 87%, some 2,100 schools out of 2,400, are open.
about 700 schools are closed - down from 950 on Wednesday.
24 schools are closed today, down from 36 on Wednesday. That is about 2% of the total of just over 1,100 schools.
A spokesman for the Department for Children, Schools and Families said: "Every lesson counts and it is right that schools should stay open wherever reasonably practicable during severe weather conditions, subject to safety considerations".
She added that if a school was open and a child did not come in because of the bad weather, a school could mark that as an authorised absence, rather than an unauthorised absence (truancy) - which is the government's main concern.
She said: "It is up to head teachers to make professional and common-sense judgements about marking absences as authorised or unauthorised during very severe weather.
"If a school which remains open is satisfied that the reason a child could not get to school was the adverse weather then that absence should be authorised; if a school judges the child could have got to school, then that absence should be unauthorised."
Inspectors, she said, would look closely at the absence figures to see if there was a particular reason.
The statistics are made public though for both authorised and unauthorised absences.
The claim that schools might close because of absence figure worries came from the Federation of Small Businesses, which has criticised schools for the closures, saying they are closing "too readily", causing problems for businesses because staff then miss work.
Stephen Alambritis, from the federation, said: "One of the concerns we have got is head teachers are worried about targets.
"If they do open the school and only a third of the kids turn up, the other 66% might be put down as absenteeism or truants, next year or the year after, by Ofsted.
"We think something should be done about that to appreciate that were schools to open and schoolkids are absent, they are not down as absentees."
Head teachers have insisted decisions to close schools are never taken lightly and that the most important issue is the safety of pupils and staff.
A major issue has been whether staff have been able to get into schools to take lessons as well as the difficulty and danger staff and pupils might face in getting into school.
Across England, the numbers of schools closed has increased in Kent and Medway (473, compared with 89 reported on Wednesday), Norfolk (368 compared with 30 on Wednesday), Suffolk (265 compared with 95) and Lincolnshire (110 - up from 47).
In Greater London, about 400 schools are closed, Hampshire has 432 closed, Cornwall 265, Oxfordshire 200, Devon 129, Gloucestershire 254, Somerset 285, Essex 376, Norfolk 368, Durham 414 and Merseyside 418.