Anxious frowns turned to smiles for thousands of teenagers who picked up their exam results last week after schools across Camden and Barnet smashed the national average for “good” GCSE grades.

Most schools reported a rise in A* to C grades, in line with a slight national increase in top marks.

But provisional borough-wide results revealed that Camden and Barnet have both seen a slight dip in the number of “good” GCSE grades.

However, pupils in both boroughs scored above the national average of 68.8pc, with 70.6pc of students in Camden achieving A* to C grades.

Camden Council leader Cllr Sarah Hayward said: “One of the students I met came to the UK at the start of Year 10 with low English language skills. Today he got seven GCSEs at grades A to C, which is amazing. “These results are testimony to the hard work of students and their teachers, and the support of their families.”

Pupils in Barnet saw a fall in the number of A* to C grades compared with last year. But provisional results revealed that students still scored significantly above the national average, with 83.1pc achieving “good” grades compared with 83.3pc last year.

In Haringey, provisional results for the percentage of five A* to C grades including mathematics and English were down on last year, with 56.7pc of pupils achieving the government benchmark.

Cllr Ann Waters, cabinet member for children and families at Haringey Council, said: “GCSE results day is always an emotional day and it has been fantastic to meet so many young people who’ve worked hard and received the grades they wanted to move onto further education, employment or training.”

Girls’ schools topped the Ham&High league table this year, with selective Henrietta Barnett School in Hampstead Garden Suburb reporting that more than 94 per cent of girls had achieved A*s or As in their GCSEs.

Independent South Hampstead High School in Hampstead was not far behind, with 92pc of girls achieving the highest grades.

Henrietta Barnett headteacher Del Cooke said: “They worked extremely hard and were rewarded for their efforts.”

Once again, the top half of the league table was dominated by independent schools, with the notable exception of King Soloman Academy in Marylebone, which saw 93pc of pupils achieve five A* to C grades.

The majority of schools reported similar results to last year, in a stable year for GCSE results.

The lack of volatility may be due to the fact that there were no drastic GCSE exam reforms this year.

But some schools did report significant jumps since last year’s results.

Among those which increased its percentage rate of top GCSE grades was all-girls Parliament Hill School near Parliament Hill Fields. It bucked the national decline in A* and A grades, with 35pc of pupils achieving the highest marks, compared with 30pc last year.

Headteacher Sue Higgins said: “We are delighted with some of our best ever exam results and for this group of students.

“They have made exceptional progress from their starting points with over one third of this cohort achieving five or more A* and A grades. “This reflects the powerful ingredients of great teaching and hard work on the part of staff and students, and great ambition and commitment on the part of our young women.”