Fiestas de San Cayetano, San Lorenzo y La Paloma

Three back-to-back neighbourhood fiestas across the first half of August, running roughly 6–15 August through Lavapiés, Embajadores and La Latina.

Street verbenas with paper decorations strung between balconies, organillo music, limonada (which is wine, not lemonade), and people dancing chotis in the street. Free.

The most genuinely old-Madrid thing that happens all year, and it takes place in the emptiest month.