A man lives in a highrise

A man lives in a highrise on the 15th floor.

Every morning, on the way to work, he takes the elevator all the way down to the 1st floor.

But when he comes home, he takes the elevator to the 8th floor and walks the rest of the way up.

The only exception is when it’s raining. Why?

The man’s a midget, and can’t reach the buttons.

When it’s raining, he has his umbrella with him, so he can reach the 15 button with it.