Zodiac signs are about as accurate as tarot readings or reading tea leaves. They’re even wrong about what they are based on. The star locations and sun precession hasn’t coincided with the original 12 zodiac constellations for centuries. People use the dates and signs as they were set by astrology tradition ages ago, but the dates when the sun changes from one constellation to the next is also absolutely arbitrary to make it match exactly 4 and a half weeks.

The personality descriptions for zodiac signs are textbook examples of cold reading. A technique of making intentionally ambiguous but agreeable affirmations so that people project their self-view onto the descriptions disregarding evidence or specifities.

It is a superstition as it is the belief on the supernatural influence of the relative apparent position of stars in the sky over the behavior and personality of individuals. It’s a, mostly, harmless superstition, but superstitious none the less.