Someone asks a simple question: why do you like thunderstorms? Most people would talk about the drama of lightning or the smell of rain. The answer here is quieter and more revealing: "it drowns out my thoughts."
The poem is only a few lines, but that reply opens up a whole inner life. The woman it describes seems to live with a mind that is too loud, full of thoughts that won't settle. Thunder, which frightens many people, is the one thing loud enough to cover them. What would normally be chaos outside becomes a kind of peace inside.
The mood is hushed and a little sad, though not hopeless. The poem never explains her thoughts or why they weigh on her, and that restraint makes it feel honest. The speaker simply reports what she was told, and the reader is left to sense how tiring constant thinking can be, and how welcome a bigger noise can feel.