The first to prepare for the Spanish summer, which lasts from 1 July to 31 August, are the TV advertisers. From the beginning of June happy groups of friends and families will begin to appear on TV screens, sitting around big tables in the garden eating paella or pizza and drinking beer. Most of the rest of Spain begins to prepare for Summer around San Juan, June 23. Those who have a beachside or country property start to ackle it up for the summer. It's amazing how many people have access to a country home or a seaside flat. In both cases the trick is inheritance. The money from the sale of Grandma's house made the flat affordable. The other option is that Grandma's house is where the family now spends Summer. The house gives the family roots, they may live in the big city, they may eat takeaway but this is where they belong. Even if you don't have a flat on the coast or a house in the country you may well have friends who do and who are willing to let you use, or even share, the place with them. If not, well, plenty of places to rent.
Then the schools close so the families have to arrange summer camps or playschemes or just the long suffering grandparents as childcare. A surprising number of people get laid off work for the summer. "Non state" teachers, the ones who work in academies or in private schools, are a good example. They find that their fixed discontinuous contracts come into play. The job will still be there when the new term starts in September/October but, in the meantime it's a case of drawing the dole or finding a summer job or, if that fails, simply hunkering down with the family and spending nothing.
Traditionally lots of Spaniards would take a month's holiday in summer. All of August for instance. Lots of local and government workplaces would close and several still do. The Health Service goes into an, almost, emergency only situation. Lots of businesses change their working hours to be from early morning to early afternoon rather than the traditional split day. Who wants to work and swelter in the summer afternoon heat?
For most people a whole month off is no longer feasible and horizons have broadened. The tendency now is maybe a fortnight at the beach/pueblo keeping some of the holiday back for Christmas and other times of the year. There's also the other possibility that the flat or pueblo house is pretty close by. Lots of Ilicitanos, people from Elche, have places on the coast in El Altet or Gran Alacant or Santa Pola for instance. That distance is commutable so people go back to the coast at the end of the reduced day. If that isn't the case then, unlike the US Marines, Spanish families do leave men behind. At least it used to be men. They were abandoned to tread the melting tarmac of, the almost deserted, Madrid while the family paddled at the coast or gossiped in the country village square. Any man in that situation could explain it quickly with the phrase "estoy de Rodríguez". Nowadays I suppose who stays behind, in the holiday spot, providing the childcare, and who commutes to work or stays in the city depends on individual circumstances. If nobody is left in the summer home to look after the kids then that's what grandparents are for.
There are lots and lots of summer habits to be observed: the beach bar or chiringuito, the silver foil wrapped tortilla sandwich, the 2pm exodus from the beach, the queue at the fountain with water containers or just trying to mimic that particular swooshing slapping sound that Spanish men elicit from their flip flops as they move along the beachside pavement. July and August are just stuffed full of "we've always done it that way" events. The municipal swimming pools as a centre of neighbourhood or small town activity, particularly for young people, the outdoor cinema, the village fiestas with their orquestas or show bands, concerts in the parks etc., etc., etc.
Strangely most Britons won't see a lot of it because so much takes place late at night as the world cools down. A concert that starts at midnight just smacks of summer madness to most of we Brits. For Spaniards of course a late night start just about gives them time to get there after the evening meal. Different rhythms.