Dozens of schools across the country have closed because of the extreme weather conditions, as the Met Office issued a “red” warning because of rising temperatures.

With temperatures potentially reaching 41 degrees Celsius on Tuesday, many schools have closed until Wednesday 20 July.

Grenoside Community Primary School in Sheffield said that it would close the school due to the “red weather warning for extreme heat and the school site being unsafe”.

King Edward VII School in Sheffield also closed its lower school on Monday afternoon and plans for it to remain closed on Tuesday, while in Lincoln, St Christopher’s School said it would be closed until Wednesday because of the heat.

In Buckinghamshire, over 50 schools have closed, while four schools announced closures across West Berkshire, and 17 full or partial closures were announced in Cambridgeshire.

Over 30 schools have closed across Oxfordshire, with many planning to remain closed until Wednesday, although some say they will wait to review the situation before deciding to close on Tuesday.

Some schools are even closing because of a lack of water supply in the extreme weather conditions.

North Wootton Academy and South Wootton Junior and Infant School in King’s Lynn, Norfolk, are closed because of low water supply in the heat.

Others have remained open but cancelled planned school trips because of the weather. St Martin’s School in Brentwood, Essex cancelled planned outings to Alton Towers and Southend-on-Sea because of the heat.

Alan Roe, headteacher of Dr Challoner’s High School in Buckinghamshire, wrote to parents on Friday to say that “due to the worsening weather forecast and the red weather alert (which was amber this morning), we have decided to close the school on Monday and Tuesday on health and safety grounds”.

He added that the school would open as planned on Wednesday morning and would close for the year at midday.

“Many of our classrooms are very uncomfortable when the temperatures are in the mid-20s,” Mr Roe said.

He said that with temperatures forecast to be up to 40 degrees Celsius on Monday and Tuesday, “we cannot keep the temperature in many of our rooms to an acceptable and safe level”, adding this decision had been taken in conjunction with several other local schools.

The NEU teaching union issued a statement saying it would “support headteachers making professional decisions to cope with the red warning, including in some circumstances to close or partially close schools”.

A Department for Education spokesperson said: “There is clear Government guidance available online to help school staff look after children in the hot weather, including the use of ventilation, keeping children hydrated and avoiding vigorous physical activity for pupils.

“Individual school leaders are responsible for managing their own local circumstances, but we are not advising schools to close.”