This article explains that white roofing might not be the best choice for San Diego, California.
“Today, the majority of new roofing is a white single-ply membrane, either TPO (thermoplastic polyolefin) or PVC (polyvinyl chloride). This is due mostly to new energy codes that require reflective roofing to reduce heat absorption into the structure. Over the past several years we have investigated moisture buildup and damage to building materials occurring underneath this type of roofing on numerous occasions. Night-time radiant cooling environments are causing detrimental moisture conditions affecting white single-ply roofing systems.”