Dozens of children are missing education in North Somerset, new figures show.
A headteachers' union said the figures are "extremely worrying", and called for more support and help in getting children back into the education system.
Department for Education figures show 39,200 children were missing education across England during this year's autumn school term, up 59% from 24,700 over the same period in 2022-23.
This means 0.5% of children in the country were missing education this autumn, compared to 0.3% two years before.
Records of the number of children missing education by local authorities only began in autumn 2022, and became mandatory in autumn 2024 — which was the first time all local authorities across England provided figures.
In North Somerset, around 80 children were missing education this autumn school term, while there were none two years prior.
This represents about 0.3% of children in the area.
Of those, 10 had been missing education for between 26 weeks and a year.
Children deemed to be missing education are those of compulsory school age who are not registered at a school and are not receiving suitable education somewhere else.
This includes children who are currently awaiting a school place and those local authorities are supporting to place into suitable education.
However, it does not include pupils who are receiving suitable home education, nor those who are registered at a school but are persistently absent.
Pepe Di’Iasio, general secretary of the Association of School and College Leaders, said the number of children missing education is "extremely worrying".
He said: "In addition to learning loss, many of these children may also be experiencing very difficult personal circumstances which impact on their welfare — such as homelessness, or mental health problems.
"It is vital that everything possible is done to support these young people and help get them back into school as soon as possible."
Dan Paskins, executive director of policy, advocacy and campaigns at Save the Children UK, said the figures are "shocking" and urged the Government to address the rising number of children missing education across the country.
He said: "There is more the UK Government can do to address these alarming absence rates, and providing further help for families with the cost of living is crucial."
Nearly half of children missing education across the country this autumn were in Years 8 to 11 (18,900) which are key to GCSE exam preparation.
Across England, 149,900 children were missing education at some point during the 2023-24 academic year, up 58% from 94,900 two years before.
Education Secretary Bridget Philipson said the Children's Wellbeing and Schools Bill, including its scrapping of the automatic right for parents to homeschool their children when safeguarding concerns are raised, will ensure children are safe and in a good place to succeed.