Never mind strawberries and Pimm's. The real sign that summer is here is at the cinema. Long school holidays lose their appeal by day four, when parents start looking for ways to get children out of the house. And Hollywood has always been happy to oblige. Action thrillers and romcoms? You got 'em!
But, somewhere along the way, the old formula has fallen apart. Box-office sales for this summer are down for the eighth year running, and are on course to finish up to 20 per cent down on last year. This would be the biggest year-on-year fall in nearly 30 years. While the figures are for the North American market, they are almost always closely mirrored in Britain. US revenues are not expected to break the $4bn (£2.4bn) mark, according to The Hollywood Reporter, which is a considerable drop on last year's $4.75bn. No film is expected to make more than $300m, for the first time since 2001.
A quiet panic is beginning to set in. Everyone is asking: whatever happened to the great summer blockbuster? Big-budget cash cows are known as "tentpoles" in the industry – the movies that keep it all propped up. Without them, the riskier projects and art-house films could never be made.
Some experts say that the figures are part of an overall decline in cinema-going, with Netflix and Amazon Prime Instant Video keeping audiences at home. Others blame the film houses for churning out pups. "People still want to go to the movies," says Paul Dergarabedian, senior analyst for film data experts Rentrak. "They just want to go to really good movies." Others say this is a blip, not a sign of a downwards trend.
So what's on the menu this summer? Dwayne Johnson plays the title role in Hercules, a retelling of the Thracian wars, and there's yet another addition to the Dawn of the Planet of the Apes franchise. But the most eagerly awaited tentpole is Guardians of the Galaxy, a 3D CGI Walt Disney bonanza, in which a bunch of misfit heroes save the universe. Chris Pratt plays a for hire, who befriends an assassin (Zoe Saldana) and what appears to be a talking shrub, in an exciting new departure for Vin Diesel. Early reviews suggest it is not nearly as bad as it sounds.
Still, it's a long way from the heady heights of 1989, when Batman was launched. Film historians say that was the start of the tentpole trend. But when you consider what else came out in 1989, it's easier to see why sales are down: there was Indiana Jones and the Last Crusade and that fake orgasm scene in When Harry Met Sally. This year we get Vin Diesel playing a shrub. Is it any wonder we'd rather stay at home?