Hacer el agosto or hacer su agosto is a Spanish expression which is used to refer to a period of time during which someone makes a lot of money without much effort and/or without scruples. 

In the literal sense, it means to ‘do the August’ or ‘do one’s August’, but it can be best translated into English as making a killing or feathering your nest. 

August is the peak of the high season and typically the month when hotels, airlines and business owners that form part of the Spanish tourism industry put up their prices considerably.

So you’d be forgiven for believing that this expression came about from the fact that money-hungry businessmen and companies shamelessly cash in to capitalise on high demand during the month most Spaniards take off for their summer holidays.

But the truth is that this saying has been around for centuries before tourists headed on masse to the Spanish coast in August.

The expression hacer el agosto actually refers to the period when Spaniards would collect their harvest and store it, with August traditionally being the busiest month for this, and therefore when peasants and landowners would have the biggest yield or make the biggest profit.

Nowadays, the saying is used mainly to refer to financial profit, and it doesn’t necessarily have to happen during August for the expression to apply, it can be at any point when someone is making a killing.

So the next time you want to say in Spanish that someone is raking it in or making a pile of money, don’t forget to use this expression, as Spaniards will be impressed. 

Examples: 

Los bares y restaurantes de Pamplona hacen su agosto durante las fiestas de San Fermín

Pamplona’s bars and restaurants make a killing during the San Fermín festival.

Elena está haciendo el agosto alquilando el piso de sus padres en Marbella a turistas ricos.

Elena is feathering her nest by renting out her parents’ flat in Marbella to rich tourists.

Siempre pasa lo mismo en verano, suben un montón los precios porque los empresarios quieren hacer su agosto.

The same thing always happens in summer, prices go up a lot because business owners want to make a killing.