Thunder is read as a loud message from above — a warning, an awakening or anger that can no longer be ignored. Dream books link it to sudden emotional force and to something demanding attention. Distant rumbling is usually read as tension building in the background of your life, while a crash right overhead stands for a conflict or truth that has finally broken out. Hearing thunder without rain is linked to quarrels that make more noise than harm. Folk traditions often treated it as the voice of the sky clearing the air. It can help to notice what is asking to be heard.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.