I live in San Diego, CA now, and grew up on a beach suburb of LA. (Although I have lived the past 20 years in the South Pacific tropics and only moved back last year) It still gets cold at night, and with only maybe a month or two, I always use a quilt on my bed. I wouldn't worry about it at all. If it gets too hot during the summer for them, they can simply fold it down when they go to bed, but still use it to display on the bed. They will be thrilled-go for it-trust me!!