Why was it always raining?
What was it with all the rain every time Cusack was outside one of his ex girlfriends apartments?
shareIt's symbolic. Rob views the world the same way Charlie Brown does. He thinks it's always (metaphorically) raining on him. So we see the literal rain falling on him in almost every outside scene.
Note that the same thing happens to Cusack's character (Lloyd Dobbler) in Say Anything. After Diane breaks up with him, there's a lot of rain in the real world to match the way he feels.
Yeah, maybe.
As an aside, do you ever notice how only in movies will people sit, walk, or have long conversations, in the rain? In real life, almost everyone does their best to get out of the rain - even if you're already soaked.
Do you ever notice in movies when it's raining you can still see the distant skyline or mountains?