Explosions in the sky

It's not as hot as yesterday, with a white film over the sky for a couple of hours until the sun decides to poke its head out, so I go on a two-hour exploration of industrial estates and suburbs to find a 'cave' for the purpose of buying shed loads of cheapo wine at rock-bottom prices to bring home. But soon it gets hot and I by the time I get back to the flat I think I've got heatstroke. It is 99 degrees. I watch clouds from the window going up in towers across the town, visibly rising, collapsing, then growing again stronger into giants patrolling the skies, waiting to go off like bombs in the blue, but they never do.