El Tiemblo has a Mediterranean climate (temperate with hot dry summers) according to the Köppen classification.
The San Juan reservoir (Embalse de San Juan, in Spanish) is located along the Alberche river between the municipalities of San Martín de Valdeiglesias, El Tiemblo, Cebreros and Pelayos de la Presa, at the south-eastern end of the Autonomous Community of Madrid, bordering on the province of Ávila.