England’s World Cup run and the sweltering weather have hit summer cinema attendance, with UK box office sales slumping 20% since June despite the release of blockbusters such as the Jurassic Park sequel and Ocean’s 8.

UK cinemas have taken £103m at the box office from 1 June to 12 July, down 19% on the £128m taken during the same period last summer.

The double-hit of England’s best performance in a World Cup since 1990 and the UK’s summer heatwave has kept cinemagoers outdoors, stripping £25m from box office revenues year-on-year so far.

The decline in ticket sales echoes a poor June on the high street, with the volume of goods sold across the whole of the retail industry down 0.5% compared with May.

Phil Clapp, the chief executive of the UK Cinema Association, said operators had got used to planning for summer slumps during big sporting years but 2018 had been worse than expected.

“We always expected the World Cup to be a challenging period for cinema. Major sporting events like that and the Olympics always present a challenge, but we didn’t expect perhaps England’s run and the continued hot weather,” he said. “It has presented a double challenge and undoubtedly cinema admissions are not where we we would like to have seen them so far.”

The big Hollywood studios planned for an attendance drought with only one major release, the heist film Ocean’s 8, timed to launch and run during most of the World Cup. Jurassic Park: Fallen Kingdom has been a box office hit in the UK but was released on 6 June, a week before the tournament kicked off.

“You don’t want to throw away a good film, so to speak, so the studios have held back releases,” said one industry executive. “The all-female Ocean’s 8 was a bit of clever counter-programming for those maybe not into the football and it is going to end out having done well, ultimately taking more than £10m.”

Despite the dire six-week figures and a number of misfires last year, including Tom Cruise’s The Mummy and Alien Covenant, the UK box office is down only 4% in the year to 12 July.

The figures to date have also been helped by the April release of Avengers: Infinity War, the biggest grossing film of the year so far.

Clapp said the box office summer was far from over as it runs traditionally from early May until early September, and big titles were now appearing, including Mamma Mia 2 and Incredibles 2, which are expected to pull in ticket-buyers through the school holidays.

Incredibles 2 took £9.6m in its opening weekend – the weekend of the World Cup final – with Mamma Mia 2 hitting screens last Friday.

Clapp is also hopeful that by the end of the year attendance numbers and box office takings will once again be up year-on-year, but admits the schedule is missing some familiar big name blockbusters such as James Bond and the final instalment in the latest Star Wars trilogy.

“We are still hopeful we will be up by the end of 2018,” he said. “There are major releases including Mary Poppins Returns and the next Fantastic Beasts coming up. There is no lack of confidence for the sector.”