Some scholars are still thinking that Arabs in Pre-Islamic era were immersed in ignorance, and they had no knowledge and sciences to help them wade through their tough life. Those scholars even believe that Pre-Islamic Arabs confined themselves with a life of passiveness, negativity and nihilism. This paper aims to demonstrate a scientific refutation of the above allegation by proving that Arabs were dealing at high level with every facet of their environment. The researcher will specify his defense of this case, by taking one issue as a model which is The Rain and its predictions. Abundant poems have mentioned rain and rainfalls in their odes. Moreover, in the documentation era, a lot of books have been authored and appeared, which are called "Anwa'“; i.e. meteorological observations. Some of such books are published nowadays, while many are still kept as manuscripts or have been lost. I concluded that Arabs have dealt with the predictions of rains and established rubrics in exploring the rainy clouds. They knew the times of rainfalls by the clouds' colors and lightening. In addition, there were persons and tribes who were the most knowing in this regard. Another conclusion in this paper, worth mentioning is that Arabs have achieved integrated Knowledge, and this paper represents a response to those who defame the Pre-Islamic Era and its people as being satisfied with eloquence, orations and poets. Furthermore, I found out that Arabs have linked up with other countries and benefited from their knowledge and was not isolated in the Arabic Peninsula.