"Fischia il vento" is a phrase that means "the wind is whistling" in Italian. It's like when you blow air out of your mouth and make a whistling sound, except it's the wind that's doing it! When the wind is blowing really hard, it can make all kinds of noises, like howling, whistling, and even roaring. Think of it like when you blow across the top of a bottle and it makes a sound - that's kind of like how the wind can make a sound too. So when someone says "fischia il vento," they're telling you that the wind is making a loud whistling sound, almost like it's singing a song. And that's all there is to it - "fischia il vento" just means "the wind is whistling."