The weekend before the official San Juan celebrations marks the start of the summer season in Tres Cantos with a schedule designed for family enjoyment. The program kicks off on Friday, June 12, with the highly anticipated opening of the municipal pools in Foresta and Embarcaciones, inviting residents to cool off and officially welcome the warm weather.

In the afternoon, popular music takes center stage at Plaza de Pablo Iglesias with the traditional Verbena para Mayores (Dance for Seniors). From 8:00 PM to 11:00 PM, attendees can enjoy an outdoor atmosphere with classic rhythms, marking an energetic start to the celebrations.

Saturday, June 13, offers a diverse day. In the morning, the Parque de Educación Vial (Road Safety Park) will host the family activity "Ruedas a la pista" (Wheels on the Track) from 10:30 AM to 1:30 PM, combining learning about road safety with traditional children's games. As evening falls, culture takes two forms: the Auditorio Municipal will broadcast the opera Romeo y Julieta live from the Teatro Real, while the Plaza de Antonio Gala will feature the "Danza en la Plaza" (Dance in the Square) show, highlighting the talent of local dance schools.

Saturday night is reserved for the main musical events. At 10:00 PM, Plaza de la Familia will come alive with a concert by Metropop, a band performing live covers of the best pop and rock hits from the 80s and 90s. Later, the Recinto Ferial (Fairgrounds) will host "La Noche es Joven con Dj’s" (The Night is Young with DJs) starting at 11:00 PM, featuring a marathon of electronic and urban music with local DJs and Alex Colomo Dj, concluding in the early morning hours with Dj Omar The Kid.

The final touch to this festive prelude will be on Sunday, June 14, at the municipal pool in Foresta. Starting at 11:00 AM, the venue will host the "Gran Fiesta del Agua" (Great Water Party), a free event for children under 14, offering aquatic games and inflatables before the municipality fully enters its main festival week.