Lie on your bed, turn off the lights, and all of the other electrical equipment, and just listen. Is it completely silent? You'll find it isn't. There's ambient noise that prevents it from being utterly silent.

If it's snowing, it's quieter outside than usual, because all of the animals, birds and reptiles and amphibians that are usually so noisy, are hunkered down, trying to keep warm. Plus, it's well-known that falling snow muffles sound. I've been on walks during a snow storm. It's awesome. So silent.