The Government confirmed in a statement today that nine were closed, 17 were having half-days and just six were open, albeit with optional attendance.

On Friday, the Government said it was for individual headteachers to make a risk assessment and take a decision as to whether to open.

Among those closed today is Granville, whose headteacher, Sue Morris, wrote to parents and guardians on Friday: “As you know, we have no outside shade at Grainville for both break and lunchtime and we have been asking children to leave the canteen this week due to the intense heat.

“I am concerned that the Met Office has issued a red extreme heat warning to parts of the UK and I worry about the health and safety of our children and staff here at Grainville.

“We have already had children suffering from heatstroke this week, in cooler weather. Therefore, I feel that it is in the best interests of us all that today will now be the last day of term for students and school will be closed on Monday 18th

“Please note that this decision has not been made lightly as I know I have asked so much of you over the year.”

Victoria College Prep was among those to opt for a half-day, with optional attendance.

Headteacher Dan Pateman told parents and guardians: “The clear recommendation made from the SCG and Public Health is that system wide school closure is not recommended. The SCG recommends that Head teachers will need to risk assess the health, safety and well-being of their staff and pupils in the context of their individual school environment in deciding the actions to take in respect of Monday and Tuesday. This is in line with the UK position with school leaders making the decision about how their schools will function during these exceptional conditions.

“With this in mind, I have taken the decision to cancel our outdoor trips for Year 5 and 6 on Monday.

“In addition, we have an outdated school building, poor ventilation, no air-conditioning, and little to none shaded areas. As the temperatures are expected to peak in the afternoon, we will be closing the school at 12 noon on Monday and Tuesday.

“Also, I am offering parents the choice of deciding (if they are able) on the best place for their son on Monday and Tuesday.”

Temperatures are currently expected to be 29 degrees tomorrow, slightly down from earlier predictions in the 30s.

On arrangements for tomorrow, a Government spokesperson said: “Schools are still assessing the risk and reviewing today so we should be able to provide further details tomorrow morning.”