The North Atlantic Oscillation (NAO) is a climatic phenomenon in the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level between the Icelandic low and the Azores high. Through fluctuations in the strength of the Icelandic low and the Azores high, it controls the strength and direction of westerly winds and storm tracks across the North Atlantic. It is part of the Arctic oscillation, and varies over time with no particular periodicity. It is found that the sun controls the Sign of the NAO index. When the index is positive rain is abundant over North Europe and less rain falls over the Mediterranean. However, a negative index brings excessive rain to the Mediterranean. and drought over Northern Europe. According to our expectation the NAO switches to negative with weak solar cycles and this brings glad tidings to Egypt. Several deluges over Egypt are explained in this context.