A prediction, or forecast, is a statement about a future event. A prediction is often, but not always, based upon experience or knowledge. There is no universal agreement about the exact difference between the two terms; different authors and disciplines ascribe different connotations.
We are not allowed to believe in the predictions of astrologers, as many of them are not true despite the fact that they some times say right. The Hadeeth says: Astrologers lie even if they say the truth sometimes. كذب المنجمون ولو صدقوا
If we believe in the astrologers, it means that we believe that they know the unseen, which is wrong.